ACPI: TAD: Split acpi_tad_rtc_read_time()

ACPI: TAD: Split acpi_tad_rtc_read_time()

Move the code converting a struct acpi_tad_rt into a struct rtc_time
from acpi_tad_rtc_read_time() into a new function, acpi_tad_rt_to_tm(),
to facilitate adding alarm support to the driver's RTC class device
interface going forward.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/9619488.CDJkKcVGEf@rafael.j.wysocki
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>