powerpc: 83xx: pci: Remove need for get_immrbase from mpc83xx_add_bridge.

Modify mpc83xx_add_bridge to get config space register base address from
the device tree instead of immr + hardcoded offset.

83xx pci nodes have this change:
    register properties now contain two address length tuples:
	First is the pci bridge register base, this has always been there.
	Second is the config base, this is new.

This is documented in dts-bindings/fsl/83xx-512x-pci.txt

The changes accomplish these things:
    mpc83xx_add_bridge no longer needs to call get_immrbase
    it uses hard coded addresses if the second register value is missing

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/boot/dts/mpc832x_rdb.dts b/arch/powerpc/boot/dts/mpc832x_rdb.dts
index b5b0ec2..226ff066 100644
--- a/arch/powerpc/boot/dts/mpc832x_rdb.dts
+++ b/arch/powerpc/boot/dts/mpc832x_rdb.dts
@@ -331,7 +331,8 @@
 		#interrupt-cells = <1>;
 		#size-cells = <2>;
 		#address-cells = <3>;
-		reg = <0xe0008500 0x100>;
+		reg = <0xe0008500 0x100		/* internal registers */
+		       0xe0008300 0x8>;		/* config space access registers */
 		compatible = "fsl,mpc8349-pci";
 		device_type = "pci";
 	};