firmware_class: Add an additional path to fw_path list

Add an additional path, /firmware/image to the list of fw paths
that request_firmware looks into for the firmware images.

Change-Id: I4b9164f222bf0a8546072de97838bf9d49dd8252
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>
Signed-off-by: Kyle Yan <kyan@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>