msm: camera: Remove unused code used to map userspace buffers.

Remove MSM_CAM_IOCTL_SET_MEM_MAP_INFO IOCTL support, since the
usage of this IOCTL is now depreciated.

Change-Id: I2ca8477fc804a80587bf40dba38904347e9b25aa
Signed-off-by: Kiran Kumar H N <hurlisal@codeaurora.org>