drm/i915/gt: Use rc6.supported flag from intel_gt for rc6_enable sysfs

Currently if rc6 is supported, it gets enabled and the sysfs files for
rc6_enable_show and rc6_enable_dev_show uses masks to check information
from drm_i915_private.

However rc6_support functions take more variables and conditions into
consideration and thus these masks are not enough for most of the modern
hardware and it is simpley lyting to the user.

Let's fix it by at least use the rc6.supported flag from intel_gt
information.
Signed-off-by: Juan Escamilla <jcescami@wasd.net>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240110010302.553597-1-jcescami@wasd.net

drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c

@@ -176,27 +176,13 @@ static u32 get_residency(struct intel_gt *gt, enum intel_rc6_res_type id)
 	return DIV_ROUND_CLOSEST_ULL(res, 1000);
 }
 
-static u8 get_rc6_mask(struct intel_gt *gt)
-{
-	u8 mask = 0;
-
-	if (HAS_RC6(gt->i915))
-		mask |= BIT(0);
-	if (HAS_RC6p(gt->i915))
-		mask |= BIT(1);
-	if (HAS_RC6pp(gt->i915))
-		mask |= BIT(2);
-
-	return mask;
-}
-
 static ssize_t rc6_enable_show(struct kobject *kobj,
 			       struct kobj_attribute *attr,
 			       char *buff)
 {
 	struct intel_gt *gt = intel_gt_sysfs_get_drvdata(kobj, attr->attr.name);
 
-	return sysfs_emit(buff, "%x\n", get_rc6_mask(gt));
+	return sysfs_emit(buff, "%x\n", gt->rc6.supported);
 }
 
 static ssize_t rc6_enable_dev_show(struct device *dev,
@@ -205,7 +191,7 @@ static ssize_t rc6_enable_dev_show(struct device *dev,
 {
 	struct intel_gt *gt = intel_gt_sysfs_get_drvdata(&dev->kobj, attr->attr.name);
 
-	return sysfs_emit(buff, "%x\n", get_rc6_mask(gt));
+	return sysfs_emit(buff, "%x\n", gt->rc6.supported);
 }
 
 static u32 __rc6_residency_ms_show(struct intel_gt *gt)