Update QNN doc (#183)

Author: kirklandsign

llm/android/LlamaDemo/docs/delegates/qualcomm_README.md

@@ -106,12 +106,12 @@ We support PTQ by default. The entire export may take ~20 minutes (Llama 3.1 8B)
 Examples:
 ```
 # 4 bits weight only quantize
-python -m extension.llm.export.export_llm base.checkpoint="${MODEL_DIR}/consolidated.00.pth" base.params="${MODEL_DIR}/params.json" model.use_kv_cache=True model.enable_dynamic_shape=False backend.qnn.enabled=True backend.qnn.quantization="qnn_16a4w" model.dtype_override="fp32" base.metadata='"{\"get_bos_id\":128000, \"get_eos_ids\":[128009, 128001]}"' export.output_name="test.pte"
+python -m extension.llm.export.export_llm base.checkpoint="${MODEL_DIR}/consolidated.00.pth" base.params="${MODEL_DIR}/params.json" model.use_kv_cache=True model.enable_dynamic_shape=False backend.qnn.enabled=True quantization.pt2e_quantize="qnn_16a4w" model.dtype_override="fp32" base.metadata='"{\"get_bos_id\":128000, \"get_eos_ids\":[128009, 128001]}"' export.output_name="test.pte"
 ```
 If the model is really big, it may require model sharding because the Qualcomm DSP is a 32bit system and has a 4GB size limit . For example for Llama 3 8B models, we need to shard the model into 4, but ExecuTorch still packages it into one PTE file. Here is an example:
 ```
 # 8 bits quantization with 4 shards
-python -m extension.llm.export.export_llm base.checkpoint="${MODEL_DIR}/consolidated.00.pth" base.params="${MODEL_DIR}/params.json" model.use_kv_cache=True model.enable_dynamic_shape=False backend.qnn.enabled=True backend.qnn.quantization="qnn_8a8w" model.dtype_override="fp32" backend.qnn.num_sharding=4 base.metadata='"{\"get_bos_id\":128000, \"get_eos_ids\":[128009, 128001]}"' export.output_name="test.pte"
+python -m extension.llm.export.export_llm base.checkpoint="${MODEL_DIR}/consolidated.00.pth" base.params="${MODEL_DIR}/params.json" model.use_kv_cache=True model.enable_dynamic_shape=False backend.qnn.enabled=True quantization.pt2e_quantize="qnn_8a8w" model.dtype_override="fp32" backend.qnn.num_sharding=4 base.metadata='"{\"get_bos_id\":128000, \"get_eos_ids\":[128009, 128001]}"' export.output_name="test.pte"
 ```
 Note: if you encountered issues below
 ```
@@ -163,7 +163,7 @@ To export Llama 3 8B instruct with the Qualcomm AI Engine Direct Backend, ensure
 * 8B models might need 16GB RAM on the device to run.
 ```
 # Please note that calibration_data must include the prompt template for special tokens.
-python -m extension.llm.export.export_llm base.tokenizer=<path_to_tokenizer.model> base.params=<path_to_params.json> base.checkpoint=<path_to_checkpoint_for_Meta-Llama-3-8B-Instruct> model.use_kv_cache=True backend.qnn.enabled=True backend.qnn.quantization="qnn_16a4w" model.enable_dynamic_shape=False backend.qnn.num_sharding=8 backend.qnn.calibration_tasks="wikitext" backend.qnn.calibration_limit=1 backend.qnn.calibration_seq_length=128 backend.qnn.optimized_rotation_path=<path_to_optimized_matrix> backend.qnn.calibration_data="<|start_header_id|>system<|end_header_id|>\n\nYou are a funny chatbot.<|eot_id|><|start_header_id|>user<|end_header_id|>\n\nCould you tell me about Facebook?<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n"
+python -m extension.llm.export.export_llm base.tokenizer=<path_to_tokenizer.model> base.params=<path_to_params.json> base.checkpoint=<path_to_checkpoint_for_Meta-Llama-3-8B-Instruct> model.use_kv_cache=True backend.qnn.enabled=True quantization.pt2e_quantize="qnn_16a4w" model.enable_dynamic_shape=False backend.qnn.num_sharding=8 backend.qnn.calibration_tasks="wikitext" backend.qnn.calibration_limit=1 backend.qnn.calibration_seq_length=128 backend.qnn.optimized_rotation_path=<path_to_optimized_matrix> backend.qnn.calibration_data="<|start_header_id|>system<|end_header_id|>\n\nYou are a funny chatbot.<|eot_id|><|start_header_id|>user<|end_header_id|>\n\nCould you tell me about Facebook?<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n"
 ```
 
 ## Pushing Model and Tokenizer