ACPICA: Cleanup for all string-to-integer conversions

ACPICA commit e2e72a351201fd58e4694418859ae2c247dafca0

Consolidate multiple versions of strtoul64 to one common version.
limit possible bases to either 10 or 16.
Handles both implicit and explicit conversions.
Added a 2-character ascii-to-hex function for GPEs and buffers.
Adds a new file, utstrtoul64.c

Link: https://github.com/acpica/acpica/commit/e2e72a35
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/exresop.c

@@ -410,12 +410,13 @@ acpi_ex_resolve_operands(u16 opcode,
 		case ARGI_INTEGER:
 
 			/*
-			 * Need an operand of type ACPI_TYPE_INTEGER,
-			 * But we can implicitly convert from a STRING or BUFFER
-			 * aka - "Implicit Source Operand Conversion"
+			 * Need an operand of type ACPI_TYPE_INTEGER, but we can
+			 * implicitly convert from a STRING or BUFFER.
+			 *
+			 * Known as "Implicit Source Operand Conversion"
 			 */
-			status =
-			    acpi_ex_convert_to_integer(obj_desc, stack_ptr, 16);
+			status = acpi_ex_convert_to_integer(obj_desc, stack_ptr,
+							    ACPI_STRTOUL_BASE16);
 			if (ACPI_FAILURE(status)) {
 				if (status == AE_TYPE) {
 					ACPI_ERROR((AE_INFO,