drm/amd/display: Add additional config guards for DCN

[Why&How]

Fix build error by protecting code with config guard
to enable building amdgpu without CONFIG_DRM_AMD_DC_DCN
enabled. This option is disabled by default for allmodconfig.
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -8469,7 +8469,7 @@ dm_determine_update_type_for_commit(struct amdgpu_display_manager *dm,
 	*out_type = update_type;
 	return ret;
 }
-
+#if defined(CONFIG_DRM_AMD_DC_DCN)
 static int add_affected_mst_dsc_crtcs(struct drm_atomic_state *state, struct drm_crtc *crtc)
 {
 	struct drm_connector *connector;
@@ -8492,6 +8492,7 @@ static int add_affected_mst_dsc_crtcs(struct drm_atomic_state *state, struct drm
 
 	return drm_dp_mst_add_affected_dsc_crtcs(state, &aconnector->mst_port->mst_mgr);
 }
+#endif
 
 /**
  * amdgpu_dm_atomic_check() - Atomic check implementation for AMDgpu DM.
@@ -8545,6 +8546,7 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 	if (ret)
 		goto fail;
 
+#if defined(CONFIG_DRM_AMD_DC_DCN)
 	if (adev->asic_type >= CHIP_NAVI10) {
 		for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 			if (drm_atomic_crtc_needs_modeset(new_crtc_state)) {
@@ -8554,7 +8556,7 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 			}
 		}
 	}
-
+#endif
 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 		if (!drm_atomic_crtc_needs_modeset(new_crtc_state) &&
 		    !new_crtc_state->color_mgmt_changed &&