ACPI: TAD: Split three functions to untangle runtime PM handling

ACPI: TAD: Split three functions to untangle runtime PM handling

Move the core functionality of acpi_tad_get_real_time(),
acpi_tad_wake_set(), and acpi_tad_wake_read() into separate functions
called __acpi_tad_get_real_time(), __acpi_tad_wake_set(), and
__acpi_tad_wake_read(), respectively, which can be called from
code blocks following a single runtime resume of the device.

This will facilitate adding alarm support to the RTC class device
interface of the driver 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>
Link: https://patch.msgid.link/23076728.EfDdHjke4D@rafael.j.wysocki