drm: kill get_reg_ofs callback

Every driver used the default implementation. Fold that one into
the only callsite and drop the callback.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index 2fea2e6..ee879d6 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -515,7 +515,7 @@
 	return 0;
 }
 
-resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
+static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
 {
 #ifdef __alpha__
 	return dev->hose->dense_mem_base - dev->hose->mem_space->start;
@@ -524,8 +524,6 @@
 #endif
 }
 
-EXPORT_SYMBOL(drm_core_get_reg_ofs);
-
 /**
  * mmap DMA memory.
  *
@@ -612,7 +610,7 @@
 #endif
 	case _DRM_FRAME_BUFFER:
 	case _DRM_REGISTERS:
-		offset = dev->driver->get_reg_ofs(dev);
+		offset = drm_core_get_reg_ofs(dev);
 		vma->vm_flags |= VM_IO;	/* not in core dump */
 		vma->vm_page_prot = drm_io_prot(map->type, vma);
 #if !defined(__arm__)