media: i2c: imx500: input tensor injection

Input tensor injection is a debug feature that allows a user-controlled
input to be passed directly to IMX500's inference engine (bypassing the
in-built ISP).

Three new custom controls are added to ENABLE_INJECTION before streaming
begins, to provide appropriate input tensors via an INPUT_TENSOR_FD, and
to provide notification of DNN results in the sensor output via
INJECTION_CMP_FRM.

Signed-off-by: Richard Oliver <richard.oliver@raspberrypi.com>

Author: roliver-rpi