We should avoid touching registers that are on the power down well
when we don't need to, because if we touch these registers when the
power well is disabled we'll get tons of "unclaimed register"
messages. This commit fixes some of these messages.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>