85xx: Introduce CONFIG_SYS_PCI*_IO_VIRT for FSL boards

Introduce a new define to seperate out the virtual address that PCI
IO space is at from the physical address.  In most situations these are
mapped 1:1.  However any code accessing the bus should use VIRT.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Andy Fleming <afleming@freescale.com>
diff --git a/board/freescale/mpc8536ds/tlb.c b/board/freescale/mpc8536ds/tlb.c
index ec76d5c7..35a13d4 100644
--- a/board/freescale/mpc8536ds/tlb.c
+++ b/board/freescale/mpc8536ds/tlb.c
@@ -63,7 +63,7 @@
 		      0, 2, BOOKE_PAGESZ_1G, 1),
 
 	/* *I*G* - PCI I/O */
-	SET_TLB_ENTRY(1, CONFIG_SYS_PCI1_IO_PHYS, CONFIG_SYS_PCI1_IO_PHYS,
+	SET_TLB_ENTRY(1, CONFIG_SYS_PCI1_IO_VIRT, CONFIG_SYS_PCI1_IO_PHYS,
 		      MAS3_SX|MAS3_SW|MAS3_SR, MAS2_I|MAS2_G,
 		      0, 3, BOOKE_PAGESZ_256K, 1),