power: rk3399: Print RTC when resetting chipset.
power: rk3399: Print RTC when resetting chipset.

In order to help correlate EC logs with those from the kernel, it was
suggested that the EC could periodically print the RTC time.  This
commit prints out the RTC time when a chipset reset is requested.

BUG=chrome-os-partner:57731
BRANCH=gru
TEST=Build and flash kevin.  Trigger watchdog from kernel and verify
that RTC time is printed when the chipset is reset.

Change-Id: Idc9a815c3337f720d41d16e0d844b4c1ea6728d8
Signed-off-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@google.com>
Reviewed-on: https://chromium-review.googlesource.com/388857
Commit-Ready: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Tested-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Reviewed-by: Shawn N <5259333ce42e3ace6a73988cec7115ed9d3a661a@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec