drm/radeon/kms: fix vram setup on rs600/rs690/rs740

Don't remap vram to 0 on IGP chips.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/rs400.c b/drivers/gpu/drm/radeon/rs400.c
index 8d12b8a..eda6d757 100644
--- a/drivers/gpu/drm/radeon/rs400.c
+++ b/drivers/gpu/drm/radeon/rs400.c
@@ -352,7 +352,7 @@
 	u32 tmp;
 
 	/* Setup GPU memory space */
-	tmp = G_00015C_MC_FB_START(RREG32(R_00015C_NB_TOM));
+	tmp = RREG32(R_00015C_NB_TOM);
 	rdev->mc.vram_location = G_00015C_MC_FB_START(tmp) << 16;
 	rdev->mc.gtt_location = 0xFFFFFFFFUL;
 	r = radeon_mc_setup(rdev);