drm/i915: Move psr unlock out from the pipe update critical section

Do the PSR unlock after the vblank evade critcal section is
fully over, not before.

Cc: Manasi Navare <navaremanasi@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230901130440.2085-2-ville.syrjala@linux.intel.com


Reviewed-by: Manasi Navare <navaremanasi@chromium.org>
Reviewed-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>