msm: ssr: Reset the crash shutdown flag on SSR completion

The crash shutdown flag is currently set for a subsystem when SSR
is triggered as a result of an err fatal interrupt or a watchdog
bite. If a kernel panic happens while restarting the subsystem in
this case, since the necessary flushing of caches/cleanup would
have been done already, we will not need to set the force_stop_gpio
again. In the case of coupled restart however, since the flag is not
set, the force_stop_gpio is set and the necessary cleanup is done for
the subsystem that is being restarted due to an SSR on a coupled
subsystem.

Currently, in the case of a coupled restart happening after a wdog
bite/ error fatal, the flushing of caches is not done since the crash
flag is still set. Reset the flag if subsystem powerup is successful
to correct this.

Change-Id: I32272762f0c27efcc0ede74578f78697c82eca20
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>