ASoC: sun8i-codec: Fix setting DAI data format

Use the correct mask for this two-bit field. This fixes setting the DAI
data format to RIGHT_J or DSP_A.

Fixes: 36c68493

 ("ASoC: Add sun8i digital audio codec")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20200217064250.15516-7-samuel@sholland.org
Signed-off-by: Mark Brown <broonie@kernel.org>