powerpc/83xx: Add PCI-E support for all MPC83xx boards with PCI-E

This patch adds pcie nodes to the appropriate dts files, plus adds
some probing code for the boards.

Also, remove of_device_is_avaliable() check from the mpc837x_mds.c
board file, as mpc83xx_add_bridge() has the same check now.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/83xx/mpc837x_rdb.c b/arch/powerpc/platforms/83xx/mpc837x_rdb.c
index 1d09654..3d7b953 100644
--- a/arch/powerpc/platforms/83xx/mpc837x_rdb.c
+++ b/arch/powerpc/platforms/83xx/mpc837x_rdb.c
@@ -38,6 +38,8 @@
 #ifdef CONFIG_PCI
 	for_each_compatible_node(np, "pci", "fsl,mpc8349-pci")
 		mpc83xx_add_bridge(np);
+	for_each_compatible_node(np, "pci", "fsl,mpc8314-pcie")
+		mpc83xx_add_bridge(np);
 #endif
 	mpc837x_usb_cfg();
 }