drm/radeon: move IB pool to 1MB offset

Even GPUs can have a null pointer dereference, so move
the IB pool to another offset to catch those.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index d48bd30..55f17f9 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -123,6 +123,7 @@
 #define CAYMAN_RING_TYPE_CP2_INDEX		2
 
 /* hardcode those limit for now */
+#define RADEON_VA_IB_OFFSET			(1 << 20)
 #define RADEON_VA_RESERVED_SIZE			(8 << 20)
 #define RADEON_IB_VM_MAX_SIZE			(64 << 10)