Clock: use mCalendar to get seconds

We haz teh calendar already. No need to create a new one to get the seconds.

Change-Id: Iccfc6e25367ad57a99bf27c29311e260b5e276d8
Signed-off-by: Tianrui Guo <tianrui@pac-rom.com>
Merge remote-tracking branch 'base/kitkat-staging' into kitkat-legacy-staging