drm/radeon/kms: move r7xx/evergreen to its own vram_gtt setup function

MC_VM_FB_LOCATION is at a different offset between r6xx and r7xx/evergreen.
The location is needed for vram setup on fusion chips.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index a355259..93b1c68 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1161,7 +1161,7 @@
  * Note: GTT start, end, size should be initialized before calling this
  * function on AGP platform.
  */
-void r600_vram_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc)
+static void r600_vram_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc)
 {
 	u64 size_bf, size_af;