msm: camera: increase the v4l2 event-queue size

Due to many SOF/REG and other event updates, some of the commands are dropping
off the queues. This patch increases the queue size to avoid this issue.

Signed-off-by: Azam Sadiq Pasha Kapatrala Syed <akapatra@codeaurora.org>
Signed-off-by: Iliyan Malchev <malchev@google.com>