msm: camera: isp: print out fourcc value in case of format error

Adds print of the FOURCC string value of image format, in case when
unsupported format is supplied, to make debugging easier.

Change-Id: I7e6e2775e39b4ce13d6b002d60746a3eb1eb60c7
Signed-off-by: Petar Sivenov <psiven@codeaurora.org>