acpi/Kconfig: move \_SB scope out of ACPI_CPU_STRING

In ACPI 1.0 the processor objects were inside the \_PR scope, but since
ACPI 2.0 the \_SB scope can be used for that. Outside of coreboot some
firmwares still used the \_PR scope for a while for legacy ACPI 1.0 OS
compatibility, but apart from that the \_PR scope is deprecated.
coreboot already uses the \_SB scope for the processor devices
everywhere, so move the \_SB scope out of the ACPI_CPU_STRING to the
format string inside the 3 snprintf statements that use the
ACPI_CPU_STRING.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Suggested-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Change-Id: I76f18594a3a623b437a163c270547d3e9618c31a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75167
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Tim Wawrzynczak <inforichland@gmail.com>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/cpu/amd/pi/00730F01/Kconfig

@@ -10,6 +10,6 @@ if CPU_AMD_PI_00730F01
 
 config ACPI_CPU_STRING
 	string
-	default "\\_SB.P%03d"
+	default "P%03d"
 
 endif # CPU_AMD_PI_00730F01