drm/amdgpu: drop old ip definitions for gfxhub and mmhub

The gfxhub and mmhub code are now helpers for gmc rather
than standalone IPs.  When that changes these were left
over.  Remove them.
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.h

@@ -30,7 +30,5 @@ void gfxhub_v1_0_set_fault_enable_default(struct amdgpu_device *adev,
 					  bool value);
 void gfxhub_v1_0_init(struct amdgpu_device *adev);
 u64 gfxhub_v1_0_get_mc_fb_offset(struct amdgpu_device *adev);
-extern const struct amd_ip_funcs gfxhub_v1_0_ip_funcs;
-extern const struct amdgpu_ip_block_version gfxhub_v1_0_ip_block;
 
 #endif

drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.h

@@ -36,7 +36,4 @@ void mmhub_v1_0_initialize_power_gating(struct amdgpu_device *adev);
 void mmhub_v1_0_update_power_gating(struct amdgpu_device *adev,
                                 bool enable);
 
-extern const struct amd_ip_funcs mmhub_v1_0_ip_funcs;
-extern const struct amdgpu_ip_block_version mmhub_v1_0_ip_block;
-
 #endif