msm: camera: cpp: Fix cpp ioctl errors

Fix the following two issues:

1. Copying error in case of 64bit compat mode caused by
calling copy_from_user() over a kernel space address.
Fix this by calling memcpy() in case of 64bit compat mode.

2. Invalid length caused by passing size of 32bit
compat structure from user space. Fix this by patching
up the size of the argument to its 64bit counterpart.

Change-Id: I704e7535fe9a9f72b31427e3121beb77056979c8
Signed-off-by: Seemanta Dutta <seemanta@codeaurora.org>