RTC: time drifting caused by system suspend/resume

RTC: time drifting caused by system suspend/resume

BZ: 20145

RTC interface provides time in second granularity, this causes half
second error accumulation each time system goes in and out of
suspension.
Change ported from commit 641a260ee5342ff42bdd500f93af5083c096f6f4
in UMG 2.6.35 tree.
Another problem fixed in this patch is that "rtc_mrst" platform device
gets registered twice in arch/x86/platform/mrst/vrtc.c and
drivers/rtc/rtc-mrst.c respectively, this would cause a failure for
the second platform device registration. Remove the one in vrtc.c

Change-Id: I9ea350f1f299033bb88e5a19b20caf71b79fec18
Signed-off-by: Fei Yang <fei.yang@intel.com>
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Reviewed-on: http://android.intel.com:8080/33112
Tested-by: Ng, Cheon-woei <cheon-woei.ng@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>