msm: camera: hyp: To fix Stack overflow

Getting stack overflow due to wrong cmd when copy_from_user.
To avoid this added check for cmd, if cmd is valid then
copy_from_user else return error.

Change-Id: I4574cb6da94bea8a8ccd7d65fc6a526ccc90d46d
Signed-off-by: Vikram Sharma <vikramsa@codeaurora.org>