ASoC: sun4i-i2s: Fix sun8i tx channel offset mask

Although not causing any noticeable issues, the mask for the
channel offset is covering too many bits.
Signed-off-by: Marcus Cooper <codekipper@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sunxi/sun4i-i2s.c

@@ -110,7 +110,7 @@
 
 #define SUN8I_I2S_TX_CHAN_MAP_REG	0x44
 #define SUN8I_I2S_TX_CHAN_SEL_REG	0x34
-#define SUN8I_I2S_TX_CHAN_OFFSET_MASK		GENMASK(13, 11)
+#define SUN8I_I2S_TX_CHAN_OFFSET_MASK		GENMASK(13, 12)
 #define SUN8I_I2S_TX_CHAN_OFFSET(offset)	(offset << 12)
 #define SUN8I_I2S_TX_CHAN_EN_MASK		GENMASK(11, 4)
 #define SUN8I_I2S_TX_CHAN_EN(num_chan)		(((1 << num_chan) - 1) << 4)