rtc: Fix set RTC time delay 500ms on some Zhaoxin SOCs

zhaoxin inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I54V04


CVE: NA

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When the RTC divider is changed from reset to an operating time base,
the first update cycle should be 500ms later. But on some Zhaoxin SOCs,
this first update cycle is one second later.
So set RTC time on these Zhaoxin SOCs will causing 500ms delay.
Skip setup RTC divider on these SOCs in mc146818_set_time to fix it.

Signed-off-by: LeoLiu-oc <LeoLiu-oc@zhaoxin.com>