mpc83xx: Make distinct caddy2 config

vme8349.h contains two separate boards: The vme8349 itself, and the
caddy2 board. The caddy2 board is chosen by setting certain config
variables. Create a proper config file for the caddy2 board to make
Kconfig migration easier.

Furthermore, simplify the vme8349 and caddy2 configs by keeping only the
options necessary for each board.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/pci/pci_auto.c b/drivers/pci/pci_auto.c
index f5e4684..1a3bf70 100644
--- a/drivers/pci/pci_auto.c
+++ b/drivers/pci/pci_auto.c
@@ -359,7 +359,8 @@
 		      PCI_DEV(dm_pci_get_bdf(dev)));
 		break;
 #endif
-#if defined(CONFIG_ARCH_MPC834X) && !defined(CONFIG_TARGET_VME8349)
+#if defined(CONFIG_ARCH_MPC834X) && !defined(CONFIG_TARGET_VME8349) && \
+		!defined(CONFIG_TARGET_CADDY2)
 	case PCI_CLASS_BRIDGE_OTHER:
 		/*
 		 * The host/PCI bridge 1 seems broken in 8349 - it presents