drm/i915/gt: Remove #ifdef guards for PM related functions

Instead of defining two versions of intel_sysfs_rc6_init(), one for each
value of CONFIG_PM, add a check on !IS_ENABLED(CONFIG_PM) early in the
function. This will allow the compiler to automatically drop the dead
code when CONFIG_PM is disabled, without having to use #ifdef guards.

This has the advantage of always compiling these functions in,
independently of any Kconfig option. Thanks to that, bugs and other
regressions are subsequently easier to catch.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221129191942.138244-13-paul@crapouillou.net

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

@@ -164,7 +164,6 @@ sysfs_gt_attribute_r_func(struct kobject *kobj, struct attribute *attr,
 								 NULL);			\
 	INTEL_GT_ATTR_RO(_name)
 
-#ifdef CONFIG_PM
 static u32 get_residency(struct intel_gt *gt, enum intel_rc6_res_type id)
 {
 	intel_wakeref_t wakeref;
@@ -300,7 +299,7 @@ static void intel_sysfs_rc6_init(struct intel_gt *gt, struct kobject *kobj)
 {
 	int ret;
 
-	if (!HAS_RC6(gt->i915))
+	if (!IS_ENABLED(CONFIG_PM) || !HAS_RC6(gt->i915))
 		return;
 
 	ret = __intel_gt_sysfs_create_group(kobj, rc6_attr_group);
@@ -329,11 +328,6 @@ static void intel_sysfs_rc6_init(struct intel_gt *gt, struct kobject *kobj)
 				 gt->info.id, ERR_PTR(ret));
 	}
 }
-#else
-static void intel_sysfs_rc6_init(struct intel_gt *gt, struct kobject *kobj)
-{
-}
-#endif /* CONFIG_PM */
 
 static u32 __act_freq_mhz_show(struct intel_gt *gt)
 {