ACPI: x86: cmos_rtc: Improve coordination with ACPI TAD driver

ACPI: x86: cmos_rtc: Improve coordination with ACPI TAD driver

If a CMOS RTC (PNP0B00/PNP0B01/PNP0B02) device coexists with an ACPI
TAD (timer and event alarm device, ACPI000E), the ACPI TAD driver will
attempt to install the CMOS RTC address space hanlder that has been
installed already and the TAD probing will fail.

Avoid that by changing acpi_install_cmos_rtc_space_handler() to return
zero and acpi_remove_cmos_rtc_space_handler() to do nothing if the CMOS
RTC address space handler has been installed already.

Fixes: 596ca52a56da ("ACPI: TAD: Install SystemCMOS address space handler for ACPI000E")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2415111.ElGaqSPkdT@rafael.j.wysocki