ASoC: wm5102: Remove set of volume update bits for output 3R

The earpiece on wm5102 is mono, thus there is no output 3R. Don't toggle
the volume update bits for this output, although worth noting that doing
so had no negative effects it is just redundant.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>