display: fix compilation when CONFIG_DEBUG_FS is disabled

Fix compilation error when CONFIG_DEBUG_FS is disabled in
kona-perf_defconfig.

Change-Id: I7f6e942e4af9fab1e3cb9fe053401a241597a81f
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Samantha Tran <samtran@codeaurora.org>

rotator/sde_rotator_debug.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2015-2019, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2015-2020, The Linux Foundation. All rights reserved.
  */
 
 #ifndef __SDE_ROTATOR_DEBUG_H__
@@ -34,7 +34,8 @@ enum sde_rot_dbg_evtlog_flag {
 	sde_rot_evtlog_tout_handler(false, __func__, ##__VA_ARGS__, \
 		SDE_ROT_EVTLOG_TOUT_DATA_LIMITER)
 
-#if defined(CONFIG_MSM_SDE_ROTATOR_EVTLOG_DEBUG)
+#if defined(CONFIG_MSM_SDE_ROTATOR_EVTLOG_DEBUG) && \
+	defined(CONFIG_DEBUG_FS)
 void sde_rot_evtlog(const char *name, int line, int flag, ...);
 void sde_rot_evtlog_tout_handler(bool queue, const char *name, ...);
 #else