ACPI: x86: cmos_rtc: Clean up address space handler driver

ACPI: x86: cmos_rtc: Clean up address space handler driver

Make multiple changes that do not alter functionality to the CMOS RTC
ACPI address space handler driver, including the following:

 - Drop the unused .detach() callback from cmos_rtc_handler.

 - Rename acpi_cmos_rtc_attach_handler() to acpi_cmos_rtc_attach().

 - Rearrange acpi_cmos_rtc_space_handler() to reduce the number of
   redundant checks and make white space follow the coding style.

 - Adjust an error message in acpi_install_cmos_rtc_space_handler()
   and make the white space follow the coding style.

 - Rearrange acpi_remove_cmos_rtc_space_handler() and adjust an error
   message in it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/5094429.31r3eYUQgx@rafael.j.wysocki