Revert "ASoC: Mark WM5100 register map cache only when going into BIAS_OFF"

This reverts commit 11a17e56
(e53e4173 upstream) as it breaks the
build.

Reported-by: Tim Gardner <rtg.canonical@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>