OpenVINO backend: enable fallback for openVINO to CPU backend

Author: zhaixuejun1993

ggml/src/ggml-openvino/ggml-decoder.cpp

@@ -1307,10 +1307,10 @@ void GgmlOvDecoder::compute_node_dynamic_dims() {
             if (src == nullptr) {
                 continue;
             }
-            struct ggml_tensor * root_src = nullptr;
-            // if (src->org_src) {
-            //     root_src = src->org_src;
-            // }
+            ggml_tensor * root_src = nullptr;
+            if (src->org_src) {
+                root_src = src->org_src;
+            }
             if (root_src) {
                 if (is_inp_tok(root_src, node) || is_inp_pos(root_src, node) || is_output_idx(root_src, node)) {
                     m_node_dynamic_dims[root_src] = 0;
@@ -1388,7 +1388,7 @@ void GgmlOvDecoder::compute_node_dynamic_dims() {
             // identifies the dynamic dim even when two dims share the same size.
             m_node_dynamic_dims[node] = -1;
             if (m_node_dynamic_dims[node->src[0]] != -1) {
-                if (node->src[0]->op == GGML_OP_NONE) {
+                if (node->src[0]->op == GGML_OP_NONE && node->src[0]->org_src == nullptr) {
                     m_node_dynamic_dims[node] = m_node_dynamic_dims[node->src[0]];
                     break;
                 }

ggml/src/ggml-openvino/ggml-decoder.h

@@ -269,7 +269,7 @@ class GgmlOvDecoder : public ov::frontend::ggml::GgmlDecoder {
     void update_io(ggml_cgraph * cgraph);
 
     inline static bool is_inp_tok(const ggml_tensor * tensor, const ggml_tensor * op) {
-        return op->op == GGML_OP_GET_ROWS && tensor == op->src[1] && op->src[0]->op == GGML_OP_NONE;
+        return op->op == GGML_OP_GET_ROWS && tensor == op->src[1] && op->src[0]->op == GGML_OP_NONE && op->src[0]->org_src == nullptr;
     }
 
     inline static bool is_inp_pos(const ggml_tensor * tensor, const ggml_tensor * op) {