drm/i915/pxp: Use to_gt() helper

Use to_gt() helper consistently throughout the codebase.
Pure mechanical s/i915->gt/to_gt(i915). No functional changes.
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211214193346.21231-9-andi.shyti@linux.intel.com

drivers/gpu/drm/i915/pxp/intel_pxp_tee.c

@@ -14,7 +14,9 @@
 
 static inline struct intel_pxp *i915_dev_to_pxp(struct device *i915_kdev)
 {
-	return &kdev_to_i915(i915_kdev)->gt.pxp;
+	struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
+
+	return &to_gt(i915)->pxp;
 }
 
 static int intel_pxp_tee_io_message(struct intel_pxp *pxp,