[PATCH] drm/amd/display: add stub for crtc_debugfs_init()

[Randy Dunlap <rdunlap@infradead.org>]

Fix build error when CONFIG_DEBUG_FS is not enabled by adding a
stub function for crtc_debugfs_init().

Eliminates this build error:

../drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c: In function ‘amdgpu_dm_crtc_late_register’:
../drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:6599:2: error: implicit declaration of function ‘crtc_debugfs_init’; did you mean ‘amdgpu_debugfs_init’? [-Werror=implicit-function-declaration]
  crtc_debugfs_init(crtc);
  ^~~~~~~~~~~~~~~~~
  amdgpu_debugfs_init

Fixes: 86bc22191892 ("drm/amd/display: Support crc on specific region")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c         |    2 --
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.h |    6 ++++++
 2 files changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -57,9 +57,7 @@
 #include "amdgpu_dm_irq.h"
 #include "dm_helpers.h"
 #include "amdgpu_dm_mst_types.h"
-#if defined(CONFIG_DEBUG_FS)
 #include "amdgpu_dm_debugfs.h"
-#endif
 #include "amdgpu_dm_psr.h"
 
 #include "ivsrcid/ivsrcid_vislands30.h"
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.h
@@ -31,6 +31,12 @@
 
 void connector_debugfs_init(struct amdgpu_dm_connector *connector);
 void dtn_debugfs_init(struct amdgpu_device *adev);
+
+#ifdef CONFIG_DEBUG_FS
 void crtc_debugfs_init(struct drm_crtc *crtc);
+#else
+static inline void crtc_debugfs_init(struct drm_crtc *crtc)
+{}
+#endif
 
 #endif