mb/siemens/mc_bdx1: Fix IASL warning reported as error

Latest IASL version (20200717) leads to a build error on 4.11_branch.

dsdt.asl 1121: Device (UNC0)
Warning 3073 - Multiple types (Device object requires either a _HID or
_ADR, but not both)

This warning reported as error was ignored in older IASL versions.
The address object (_ADR) is not needed because a valid hardware ID
(_HID) for the device is available.

Change-Id: Iae5c91739ed9caea2dbb5996e2f093ed6fc47e93
Signed-off-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46129
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Christian Walter <christian.walter@9elements.com>

src/mainboard/siemens/mc_bdx1/dsdt.asl

@@ -261,7 +261,6 @@ DefinitionBlock(
 				Return (0xff)
 			}
 
-			Name (_ADR, 0x00)
 			Method (_STA, 0, NotSerialized)
 			{
 				Return (0xf)