acpi: Change Processor ACPI Name (Intel only)

The ACPI Spec 2.0 states, that Processor declarations should be made
within the ACPI namespace \_SB and not \_PR anymore. \_PR is deprecated
and is removed here for Intel CPUs only.

Tested on:
* X11SSH (Kabylake)
* CFL Platform
* Asus P8Z77-V LX2 and Windows 10

FWTS does not return FAIL anymore on ACPI tests

Tested-by: Angel Pons <th3fanbus@gmail.com>
Change-Id: Ib101ed718f90f9056d2ecbc31b13b749ed1fc438
Signed-off-by: Christian Walter <christian.walter@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37814
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/soc/intel/common/block/acpi/acpi.c b/src/soc/intel/common/block/acpi/acpi.c
index bed4401..b848db44 100644
--- a/src/soc/intel/common/block/acpi/acpi.c
+++ b/src/soc/intel/common/block/acpi/acpi.c
@@ -433,7 +433,7 @@
 				plen = 0;
 			}
 
-			/* Generate processor \_PR.CPUx */
+			/* Generate processor \_SB.CPUx */
 			acpigen_write_processor((cpu_id) * cores_per_package +
 						core_id, pcontrol_blk, plen);