Revert "Revert "mako: msm: board: enable HS200 bus speed mode support""

This reverts commit e039dcb2ebcf3afcfc133caefb60a6836f437a63.
msm: camera: nullify pointers after kfree and fix the memory leaks

nullify pointers after kfree and remove unnecessary kmallocs

Also fix the memory leaks. should free the memory after v4l2_event_dequeue()
even if there are some errors in copy_to/from_user(). Because entry was
already removed from its own list after v4l2_event_dequeue().

Change-Id: I733538c2fd76a6b77cfd8d6b780caebcb3fd70a8