drm/amdgpu/sdma4: Remove unused header file from sdma_v4_0.c

Remove mmhub header files inclusion which not used.
Signed-off-by: Feifei Xu <Feifei.Xu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c

@@ -31,8 +31,6 @@
 #include "sdma0/sdma0_4_0_sh_mask.h"
 #include "sdma1/sdma1_4_0_offset.h"
 #include "sdma1/sdma1_4_0_sh_mask.h"
-#include "mmhub/mmhub_1_0_offset.h"
-#include "mmhub/mmhub_1_0_sh_mask.h"
 #include "hdp/hdp_4_0_offset.h"
 #include "sdma0/sdma0_4_1_default.h"