iio: adc: at91-sama5d2_adc: fix sama7g5 realbits value

iio: adc: at91-sama5d2_adc: fix sama7g5 realbits value

commit aa5119c36d19639397d29ef305aa53a5ecd72b27 upstream.

The number of valid bits in SAMA7G5 ADC channel data register are 16.
Hence changing the realbits value to 16

Fixes: 840bf6cb983f ("iio: adc: at91-sama5d2_adc: add support for sama7g5 device")
Signed-off-by: Nayab Sayed <nayabbasha.sayed@microchip.com>
Link: https://patch.msgid.link/20250115-fix-sama7g5-adc-realbits-v2-1-58a6e4087584@microchip.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>