Revert "drm/amd/display: Skip entire amdgpu_dm build if !CONFIG_DRM_AMD_DC"

This reverts commit 1b097bcd.

[WHY & HOW]
The writeback series cause a regression in thunderbolt display.
Signed-off-by: Alex Hung <alex.hung@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/Makefile

@@ -25,24 +25,22 @@
 
 
 
-ifneq ($(CONFIG_DRM_AMD_DC),)
 AMDGPUDM = \
 	amdgpu_dm.o \
 	amdgpu_dm_plane.o \
 	amdgpu_dm_crtc.o \
 	amdgpu_dm_irq.o \
 	amdgpu_dm_mst_types.o \
-	amdgpu_dm_color.o \
-	amdgpu_dm_services.o \
-	amdgpu_dm_helpers.o \
-	amdgpu_dm_pp_smu.o \
-	amdgpu_dm_psr.o \
-	amdgpu_dm_replay.o
+	amdgpu_dm_color.o
 
 ifdef CONFIG_DRM_AMD_DC_FP
 AMDGPUDM += dc_fpu.o
 endif
 
+ifneq ($(CONFIG_DRM_AMD_DC),)
+AMDGPUDM += amdgpu_dm_services.o amdgpu_dm_helpers.o amdgpu_dm_pp_smu.o amdgpu_dm_psr.o amdgpu_dm_replay.o
+endif
+
 AMDGPUDM += amdgpu_dm_hdcp.o
 
 ifneq ($(CONFIG_DEBUG_FS),)
@@ -54,4 +52,3 @@ subdir-ccflags-y += -I$(FULL_AMD_DISPLAY_PATH)/dc
 AMDGPU_DM = $(addprefix $(AMDDALPATH)/amdgpu_dm/,$(AMDGPUDM))
 
 AMD_DISPLAY_FILES += $(AMDGPU_DM)
-endif