[media] media: venus: update firmware path with linux-firmware place

This makes firmware name and path part of venus_resources
structure and initialize it properly depending on the SoC and
firmware version.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>