disp: msm: avoid using #ifdef for configurations

Use #if IS_ENABLED() instead of #ifdef for configurations as vendor module
guidelines.

Use #if IS_ENABLED(CONFIG_XXX) instead of #ifdef CONFIG_XXX to ensure that
the code inside the #if block continues to compile if the config changes
to a tristate config in the future.

The differences are as follows:
	1.#if IS_ENABLED(CONFIG_XXX) evaluates to true when CONFIG_XXX is set to
		module (=m) or built-in (=y).
	2.#ifdef CONFIG_XXX evaluates to true when CONFIG_XXX is set to
		built-in(=y) , but doesn't when CONFIG_XXX is set to module(=m).
		Use this only when you're certain you want to do the same thing
		when the config is set to module or is disabled.

Change-Id: Ia806b9b01ad8414d0e4de027a382cb68e7fb4a6a
Signed-off-by: GG Hou <quic_renjhou@quicinc.com>

msm/sde/sde_encoder.c

@@ -4695,7 +4695,7 @@ int sde_encoder_helper_collect_misr(struct sde_encoder_phys *phys_enc,
 			nonblock, misr_value) : -ENOTSUPP;
 }
 
-#ifdef CONFIG_DEBUG_FS
+#if IS_ENABLED(CONFIG_DEBUG_FS)
 static int _sde_encoder_status_show(struct seq_file *s, void *data)
 {
 	struct sde_encoder_virt *sde_enc;
@@ -4966,7 +4966,7 @@ static int _sde_encoder_init_debugfs(struct drm_encoder *drm_enc)
 static void _sde_encoder_destroy_debugfs(struct drm_encoder *drm_enc)
 {
 }
-#endif
+#endif /* CONFIG_DEBUG_FS */
 
 static int sde_encoder_late_register(struct drm_encoder *encoder)
 {