lm3554: use struct lm3554 as storage of actual values

lm3554: use struct lm3554 as storage of actual values

BZ: 32196

There is no need to keep value in the hardware and sometimes it's even a bad
idea.

This patch partialy moves the storage from hardware to the struct lm3554 fields
and will be used later as well.

Change-Id: Ia80d465404bfb38bb24d02274ab95986d6a16870
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-on: http://android.intel.com:8080/43705
Reviewed-by: Shevchenko, Andriy <andriy.shevchenko@intel.com>
Reviewed-by: Toivonen, Tuukka <tuukka.toivonen@intel.com>
Reviewed-by: Cohen, David A <david.a.cohen@intel.com>
Tested-by: Koski, Anttu <anttu.koski@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>