iio: adc: ad7124: fix mask used for setting AIN_BUFP & AIN_BUFM bits

commit 0e33d15 upstream.

According to page 90 of the datasheet [1], AIN_BUFP is bit 6 and
AIN_BUFM is bit 5 of the CONFIG_0 -> CONFIG_7 registers.

Fix the mask used for setting these bits.

[1]: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7124-8.pdf

Fixes: 0eaecea ("iio: adc: ad7124: Add buffered input support")
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220112200036.694490-1-cosmin.tanislav@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iio/adc/ad7124.c

@@ -74,7 +74,7 @@
 #define AD7124_CONFIG_REF_SEL(x)	FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x)
 #define AD7124_CONFIG_PGA_MSK		GENMASK(2, 0)
 #define AD7124_CONFIG_PGA(x)		FIELD_PREP(AD7124_CONFIG_PGA_MSK, x)
-#define AD7124_CONFIG_IN_BUFF_MSK	GENMASK(7, 6)
+#define AD7124_CONFIG_IN_BUFF_MSK	GENMASK(6, 5)
 #define AD7124_CONFIG_IN_BUFF(x)	FIELD_PREP(AD7124_CONFIG_IN_BUFF_MSK, x)
 
 /* AD7124_FILTER_X */