msm-camera: Added the  NULL check in gemini driver.

Adding NULL check for ionhandle and y_off in gemini driver files.

CRs-Fixed: 504159

Change-Id: I6d20298183bec0c3c2c16088a936ac6f7d307da4
Signed-off-by: Katta Santhisindhu <kattas@codeaurora.org>
msm: camera: prevent invalid access through mmap

Disable access to invalid addresses through mmap.
Add appropriate range checks to ensure valid accesses
through framebuffer mmap. This prevents illegal
access into memory.

Change-Id: Ie053d9d8efe951b88f28b020dd9c2356e54723a7
CRs-Fixed: 475794
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
Merge "msm: camera: prevent invalid access through mmap"
Merge "msm-camera: Added the  NULL check in gemini driver."