ASUS F2A85-M: Split DSDT into common sections (as per Parmer)

Rearranged the F2A85-M DSDT file to match the functionality found
on Parmer.  As with the Parmer implementation, the F2A85-M dsdt.asl
file in the mainboard directory contains only #include references to
the appropriate files.

As with Parmer, some include files have no content but are left as a
template for other platforms and as placeholders for completing the
ACPI implementation for F2A85-M.

Change-Id: Ic72cb6004538ca9d9f79826b9b3c8d6aeb25017c
Signed-off-by: Kimarie Hoot <kimarie.hoot@se-eng.com>
Reviewed-on: http://review.coreboot.org/3805
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martin@se-eng.com>

src/northbridge/amd/agesa/family15tn/acpi/northbridge.asl

@@ -49,6 +49,16 @@ Device(AMRT) {
 	Name(_ADR, 0x00000000)
 } /* end AMRT */
 
+/* Dev2 is also an external GFX bridge */
+Device(PBR2) {
+	Name(_ADR, 0x00020000)
+	Name(_PRW, Package() {0x18, 4})
+	Method(_PRT,0) {
+		If(PMOD){ Return(APS2) }   /* APIC mode */
+		Return (PS2)                  /* PIC Mode */
+	} /* end _PRT */
+} /* end PBR2 */
+
 /* Dev4 GPP0 Root Port Bridge */
 Device(PBR4) {
 	Name(_ADR, 0x00040000)