drm/v3d: Fix debugfs reads of MMU regs.

They're in the hub, not the individual cores.
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190419001014.23579-1-eric@anholt.netReviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>

drivers/gpu/drm/v3d/v3d_debugfs.c

@@ -26,6 +26,10 @@ static const struct v3d_reg_def v3d_hub_reg_defs[] = {
 	REGDEF(V3D_HUB_IDENT3),
 	REGDEF(V3D_HUB_INT_STS),
 	REGDEF(V3D_HUB_INT_MSK_STS),
+
+	REGDEF(V3D_MMU_CTL),
+	REGDEF(V3D_MMU_VIO_ADDR),
+	REGDEF(V3D_MMU_VIO_ID),
 };
 
 static const struct v3d_reg_def v3d_gca_reg_defs[] = {
@@ -50,9 +54,6 @@ static const struct v3d_reg_def v3d_core_reg_defs[] = {
 	REGDEF(V3D_PTB_BPCA),
 	REGDEF(V3D_PTB_BPCS),
 
-	REGDEF(V3D_MMU_CTL),
-	REGDEF(V3D_MMU_VIO_ADDR),
-
 	REGDEF(V3D_GMP_STATUS),
 	REGDEF(V3D_GMP_CFG),
 	REGDEF(V3D_GMP_VIO_ADDR),