drm/i915/de: Replace __intel_de_wait_for_register_nowl() with intel_de_wait_fw_us_ato...

drm/i915/de: Replace __intel_de_wait_for_register_nowl() with intel_de_wait_fw_us_atomic()

Nuke the remaining _nowl() stuff from the wakelock code in the
form of __intel_de_wait_for_register_nowl(), and replace it with
intel_de_wait_fw_us_atomic() that uses the low level _fw() register
accessors in line with the rest of the code.

No change in behaviour since wakelocks are only supported on xe,
and xe doesn't have uncore.lock nor unclaimed register detection
stuff.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251110172756.2132-15-ville.syrjala@linux.intel.com
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>