drivers: sensor: grow_r502a: add upload and download template

1. Add functionality for upload and download fingerprint
template data of the R502A fingerprint sensor device.
2. change data type for data_len parameter of
transceive_packet function to uint16_t as it may hold
value 256 for dowload template data to sensor.

Signed-off-by: Dinesh Kumar K <dinesh@linumiz.com>