drm/i915/psr: Check PSR pause counter in __psr_wait_for_idle_locked

drm/i915/psr: Check PSR pause counter in __psr_wait_for_idle_locked

PSR work is using __psr_wait_for_idle_locked to ensure PSR exit is
completed before continuing to PSR activation. __psr_wait_for_idle_locked
is unlocking PSR mutex which allows PSR disable/enable and PSR
pause/resume while PSR idle is being wait. PSR enable status is already
checked after locking again PSR mutex but PSR pause counter check is
missing. Due to this PSR work may continue to PSR activation even PSR is
paused.

Fix this by checking PSR pause counter in __psr_wait_for_idle_locked after
PSR mutex is locked again.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jeevan B <jeevan.b@intel.com>
Link: https://lore.kernel.org/r/20250826074457.1992524-1-jouni.hogander@intel.com