msm: camera: isp: Add active list request flush support

If umd send flush all, isp driver flushes only pending list requests.
Currently, the expectation is that the active list and wait request
will be cleared upon receiving buf done from hardware. In corner
cases due to IRQ scheduling delay, sometimes the active list will get
stuck with one request without clearing it. This is causing flush wait
timeout at application level. This change adds stop HW and flush active
adn wait list to prevent these timeouts.

Change-Id: Ifdb318cd21859cde5d2c318e39d9a71aa0e227b3
Signed-off-by: Alok Pandey <akumarpa@codeaurora.org>
Signed-off-by: Junzhe Zou <jnzhezou@codeaurora.org>
Signed-off-by: Harsh Shah <harshs@codeaurora.org>