This patch implements RTC initialization.
1. initialization dcxo
2. rtc clock using dcxo 32k
3. export RTC_32K1V8_0 to SOC, export RTC_32K1V8_1 to WLAN
4. rtc register initialization
5. refactor the driver common part
BUG=b:80501386
BRANCH=none
TEST=Boots correctly on Kukui
Change-Id: Icccb9360a507fcbfd865b107cd3630e71c810d55
Signed-off-by: Ran Bi <ran.bi@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/31046
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
