soc/intel/common/acpi: move S0ix UUID to the condition

Move the UUID to the condition, since there is no need to assign a name
when it is only used once. Also add a comment to make clear that the
functions inside that condition are only used by the Low Power Idle S0
functionality, while the PEPD in general can be present on boards
without S0ix capability, too. For details check CB:46469.

Change-Id: Ic62c37090ad1b747f9d7d204363cc58f96ef67ef
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46468
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/common/block/acpi/acpi/pep.asl

@@ -18,10 +18,10 @@ Device(LPID)
 {
 	Name(_ADR, 0x00000000)
 	Name(_CID, EISAID("PNP0D80"))
-	Name(UUID, ToUUID("c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"))
 	Method(_DSM, 4)
 	{
-		If(Arg0 == ^UUID) {
+		/* Low Power Idle S0 helper */
+		If(Arg0 == ToUUID("c4eb40a0-6cd2-11e2-bcfd-0800200c9a66")) {
 			/*
 			 * Enum functions
 			 */