ASoC: wm5102: Revert manual speaker enable

The OUT4L and OUT4R widgets are not registered PRE_PMU or POST_PMD
events, as such the manual speaker enable on wm5102 does not actually
ever run. Furthermore since the issue actually only affected rev B of
the silicon which never shipped in volume, simply remove the work around
from the code.

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