msm: camera: Optimize burst stream stop sequence

When burst stream is done capturing burstshot, it will
configure the framedrop registers to drop all frames,
which effectively stop all activity to the bus.
When stream off is sent from HAL, the stream should be
inactive, this change will apply the write masters
disable immediately instead of applying the configuration
at frame boundary. If there is steam off command while the
stream is still active, the stop command will wait and
apply the stop at frame boundary,

Change-Id: I757dc89f0a915b78e31f68584f9198c617f6c643
Signed-off-by: Kevin Chan <ktchan@codeaurora.org>