msm_fb: Fix error in y-offset check logic in FB driver

After 4 KB alignment changes, the frame from 3rd buffer doesn't
get updated since during PUT_VSCREEN_INFO ioctl, the driver
returns -1 to userspace due to error in logic because the hole
size is not considered in calculating the logic for validity of
the y-offset. Change fixes this error.

Change-Id: Ib151970eacab4df36fb8274be0079bc814e93efe
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>