Documentation: rtc-tz update Timezone of ACPI/EFI RTC Driver Test/Example Program

Update Timezone of ACPI/EFI RTC Driver Test/Example Program, add testing for RTC_RD_TIME2
and RTC_SET_TIME2. Additional update the logic for increase/decrease testing datetime.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>