ppc/85xx: Fix compile err when PCI disabled on P1_P2_RDB

u-boot cannot be compiled after disabling CONFIG_PCI.

Place PCI related codes under #ifdef CONFIG_PCI

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>