drm/sun4i: Fix the high buffer address mask

The highest 3bits of the 4 layers buffers are all part of the same
register. However, our mask computation was wrong, leading to all the
lowest register bits being removed when we use regmap_update_bits, which
will lead to the buffers being set to some random part of the RAM.

Fix our mask.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/gpu/drm/sun4i/sun4i_backend.h

@@ -52,8 +52,8 @@
 #define SUN4I_BACKEND_LAYFB_L32ADD_REG(l)	(0x850 + (0x4 * (l)))
 
 #define SUN4I_BACKEND_LAYFB_H4ADD_REG		0x860
-#define SUN4I_BACKEND_LAYFB_H4ADD_MSK(l)		GENMASK(3 + ((l) * 8), 0)
-#define SUN4I_BACKEND_LAYFB_H4ADD(l, val)			((val) << ((l) * 8))
+#define SUN4I_BACKEND_LAYFB_H4ADD_MSK(l)		GENMASK(3 + ((l) * 8), (l) * 8)
+#define SUN4I_BACKEND_LAYFB_H4ADD(l, val)		((val) << ((l) * 8))
 
 #define SUN4I_BACKEND_REGBUFFCTL_REG		0x870
 #define SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS		BIT(1)