ACPI: processor: remove comment regarding string _UID support

ACPI 6.3 Errata A no longer allows _UID to return a string except for
Itanium (for historical reasons) as stated in section 5.2.12:

"From ACPI Specification 6.3 onward, all processor objects for all
architectures except Itanium must now use Device() objects with an
_HID of ACPI0007, and use only integer _UID values."

Therefore, the "we don't handle string _UIDs yet" comment, which
implies a missing feature, is redundant, so drop it.
Signed-off-by: Alex Hung <alex.hung@canonical.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpi_processor.c

@@ -264,7 +264,6 @@ static int acpi_processor_get_info(struct acpi_device *device)
 	} else {
 		/*
 		 * Declared with "Device" statement; match _UID.
-		 * Note that we don't handle string _UIDs yet.
 		 */
 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 						NULL, &value);