Revert "amdgpu/dc: drop dml display_mode_support.c (v2)"

This reverts commit 5e0adbff.

Unfortunately these clash with our DML update from the HW guys.
Will attempt to reroll them after.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/Makefile

@@ -10,10 +10,12 @@ CFLAGS_display_rq_dlg_helpers.o := -mhard-float -msse -mpreferred-stack-boundary
 CFLAGS_display_watermark.o := -mhard-float -msse -mpreferred-stack-boundary=4
 CFLAGS_soc_bounding_box.o := -mhard-float -msse -mpreferred-stack-boundary=4
 CFLAGS_dml_common_defs.o := -mhard-float -msse -mpreferred-stack-boundary=4
+CFLAGS_display_mode_support.o := -mhard-float -msse -mpreferred-stack-boundary=4
+
 
 DML = display_mode_lib.o display_rq_dlg_calc.o \
 	  display_rq_dlg_helpers.o display_watermark.o \
-	  soc_bounding_box.o dml_common_defs.o
+	  soc_bounding_box.o dml_common_defs.o display_mode_support.o
 
 AMD_DAL_DML = $(addprefix $(AMDDALPATH)/dc/dml/,$(DML))
 

drivers/gpu/drm/amd/display/dc/dml/display_mode_support.h

@@ -191,4 +191,9 @@ struct dml_ms_internal_vars {
 	struct _vcs_dpi_wm_calc_pipe_params_st planes[DC__NUM_PIPES__MAX];
 };
 
+int dml_ms_check(
+		struct display_mode_lib *mode_lib,
+		struct _vcs_dpi_display_e2e_pipe_params_st *e2e,
+		int num_pipes);
+
 #endif