ASoC: ad193x: Fix define of AD193X_PLL_INPUT_MASK

Current code defines AD193X_PLL_INPUT_MASK as (~0x6) which is quite
different from other MASK defines.
To make it consistent with other mask defines, define AD193X_PLL_INPUT_MASK
as 0x6 and change the code accordingly.
I think this change improves the readability.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/ad193x.h b/sound/soc/codecs/ad193x.h
index 536e5f2..1507eaa 100644
--- a/sound/soc/codecs/ad193x.h
+++ b/sound/soc/codecs/ad193x.h
@@ -11,7 +11,7 @@
 
 #define AD193X_PLL_CLK_CTRL0    0x00
 #define AD193X_PLL_POWERDOWN           0x01
-#define AD193X_PLL_INPUT_MASK   (~0x6)
+#define AD193X_PLL_INPUT_MASK   0x6
 #define AD193X_PLL_INPUT_256    (0 << 1)
 #define AD193X_PLL_INPUT_384    (1 << 1)
 #define AD193X_PLL_INPUT_512    (2 << 1)