qemu: move i440fx bits

Prepare tree for adding q35 support:
Move emulation/qemu-x86 to emulation/qemu-i440fx.
Rename some stuff to include 'i440fx'.

Change-Id: Ib8c58175c5734cfcda1b22404ef52c09d38f0462
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-on: http://review.coreboot.org/3429
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/mainboard/emulation/qemu-i440fx/devicetree.cb

@@ -0,0 +1,18 @@
+chip mainboard/emulation/qemu-i440fx
+	device cpu_cluster 0 on
+		chip cpu/qemu-x86
+			device lapic 0 on end
+		end
+	end
+	device domain 0 on
+		device pci 0.0 on end		# northbridge (i440fx)
+		chip southbridge/intel/i82371eb # southbridge
+			device pci 01.0 on end	# ISA bridge
+			device pci 01.1 on end	# IDE
+			device pci 01.3 on end	# ACPI
+			register "ide0_enable" = "1"
+			register "ide1_enable" = "1"
+			register "gpo" = "0x7fffbbff"
+		end
+	end
+end