ASoC: cs4349: Fix setting digital interface format

Mode Control - Register 02h

Digital Interface Format (DIF[2:0]) Bits 6-4

DIF2    DIF1    DIF0    Description
0       0       0       Left-Justified, up to 24-bit data
0       0       1       I²S, up to 24-bit data
0       1       0       Right-Justified, 16-bit data
0       1       1       Right-Justified, 24-bit data
1       0       0       TDM slot 0
1       0       1       TDM slot 1
1       1       0       TDM slot 2
1       1       1       TDM slot 3

The DIF_MASK is 0x70, so current code does not correctly set the DIFx
setting. Fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>