mb/asus/p5gc-mx: Implement resume from S3 support

Needs the ramstage configuration enabling of SuperIO GPIO pnp devices
for BSEL straps.

Also needs VSBGATE# to be on for ram to be powered during S3.

TESTED with 800MHz and 1067MHz FSB CPUs at the correct straps when
resuming from S3.

Change-Id: I6ac927ee9dcce15fc7621aad57969fae8f5805ca
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/19602
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/mainboard/asus/p5gc-mx/devicetree.cb b/src/mainboard/asus/p5gc-mx/devicetree.cb
index 824beed..cefa711 100644
--- a/src/mainboard/asus/p5gc-mx/devicetree.cb
+++ b/src/mainboard/asus/p5gc-mx/devicetree.cb
@@ -113,9 +113,20 @@
 					device pnp 2e.6 off end # SPI
 					device pnp 2e.7 on end # GPIO6
 					device pnp 2e.8 off end # WDTO# & PLED
-					device pnp 2e.9 on end # GPIO2-5
+					device pnp 2e.9 off end # GPIO2
+					device pnp 2e.109 on # GPIO3
+						irq 0xf0 = 0xf3 # BSEL straps to output
+						irq 0xf2 = 0x08 # INVERT GPIO33
+					end
+					device pnp 2e.209 on # GPIO4
+						irq 0xf5 = 0xf8
+					end
+					device pnp 2e.309 on  # GPIO5
+						irq 0xe0 = 0xde
+					end
 					device pnp 2e.a on # ACPI
 						irq 0x70 = 0
+						irq 0xe4 = 0x10 # VSBGATE# to power dram during S3
 					end
 					device pnp 2e.b on # HWM
 						io 0x60 = 0x290