ACPI: Eliminate CONFIG_.*{, _MODULE} #ifdef in favor of IS_ENABLED()

This commit removes all CONFIG_.*{,_MODULE} in ACPI code, replacing it
with IS_ENABLED().

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>