ASoC: tlv320dac33: Restore L/R DAC power control register

Register 0x40, 0x41 need to be restored after power up, since
it contains gain related fields, which affects playback volume.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>