drm/amdgpu: rename tonga_smumgr.h to tonga_smum.h

This conflicts with the tonga_smumgr.h from powerplay
in DKMS environement

Signed-off-by: Jammy Zhou <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Jordan Lazare <[e-mail]>

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

···
 #include <linux/firmware.h>
 #include "drmP.h"
 #include "amdgpu.h"
-#include "tonga_smumgr.h"
+#include "tonga_smum.h"
 
 MODULE_FIRMWARE("amdgpu/tonga_smc.bin");
 

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

···
 #include "drmP.h"
 #include "amdgpu.h"
 #include "tonga_ppsmc.h"
-#include "tonga_smumgr.h"
+#include "tonga_smum.h"
 #include "smu_ucode_xfer_vi.h"
 #include "amdgpu_ucode.h"