drm/amd/display: Remove unused CFLAGS entry in DML Makefile

Missed that with a previous change that removed unused files.
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -32,7 +32,6 @@ endif
 
 dml_ccflags := -mhard-float -msse $(cc_stack_align)
 
-CFLAGS_display_mode_vba.o := $(dml_ccflags)
 CFLAGS_display_mode_lib.o := $(dml_ccflags)
 CFLAGS_display_pipe_clocks.o := $(dml_ccflags)
 CFLAGS_dml1_display_rq_dlg_calc.o := $(dml_ccflags)