msm: camera: Fix possible out of bound writes in csi driver

The value csi_lane_mask which is uint16_t is controllable from userspace.
The while loop can loop for 2^16 - 1, Hence extract the required
bit combination from the userspace argument, used it for further
processing.

CRs-Fixed: 511976
Change-Id: I80b0fe7ac273352503d9705510f05debe6cbb10a
Signed-off-by: Lakshmi Narayana Kalavala <lkalaval@codeaurora.org>