drm/amdgpu: use the TTM dummy page instead of allocating one

We have a global dummy page in TTM, use that one instead of allocating a
new one.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 1ac81be..3e6f27d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -344,14 +344,6 @@ bool amdgpu_get_bios(struct amdgpu_device *adev);
 bool amdgpu_read_bios(struct amdgpu_device *adev);
 
 /*
- * Dummy page
- */
-struct amdgpu_dummy_page {
-	struct page	*page;
-	dma_addr_t	addr;
-};
-
-/*
  * Clocks
  */
 
@@ -1505,7 +1497,7 @@ struct amdgpu_device {
 	/* MC */
 	struct amdgpu_gmc		gmc;
 	struct amdgpu_gart		gart;
-	struct amdgpu_dummy_page	dummy_page;
+	dma_addr_t			dummy_page_addr;
 	struct amdgpu_vm_manager	vm_manager;
 	struct amdgpu_vmhub             vmhub[AMDGPU_MAX_VMHUBS];