The RS_PLUG and RS_UNPLUG interrupt masks are always written as 1 so
those writes are redundant and can be deleted.

This makes it completely clear in the code that only the TS_PLUG and
TS_UNPLUG masks are being changed.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20211116163901.45390-3-rf@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>