mb/asus/p2b: list all unused Super I/O resources

Some Super I/O resources were unused and not listed, causing warnings
during resource allocation. Suppress these warnings by setting them to
zero.

Change-Id: I28e37c3a58f3a6b5a613733f26ac18d6a7b3be2e
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41459
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/asus/p2b/devicetree.cb

@@ -18,6 +18,7 @@ chip northbridge/intel/i440bx		# Northbridge
           device pnp 3f0.1 on		# Parallel port
             io 0x60 = 0x378
             irq 0x70 = 7
+            drq 0x74 = 0
           end
           device pnp 3f0.2 on		# COM1
             io 0x60 = 0x3f8
@@ -34,6 +35,9 @@ chip northbridge/intel/i440bx		# Northbridge
             irq 0x72 = 12		# PS/2 mouse interrupt
           end
           device pnp 3f0.7 on		# GPIO 1
+            io 0x60 = 0
+            io 0x62 = 0
+            irq 0x70 = 0
           end
           device pnp 3f0.8 on		# GPIO 2
           end