85xx: separate FLASH BASE virtual from physical address

Added a CONFIG_SYS_FLASH_BASE_PHYS for use as the physical address and
maintain CONFIG_SYS_FLASH_BASE as the virtual address of the flash.

This allows us to deal with 36-bit phys on these boards in the future.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Andy Fleming <afleming@freescale.com>
diff --git a/board/freescale/mpc8536ds/mpc8536ds.c b/board/freescale/mpc8536ds/mpc8536ds.c
index 2b17612..e369d09 100644
--- a/board/freescale/mpc8536ds/mpc8536ds.c
+++ b/board/freescale/mpc8536ds/mpc8536ds.c
@@ -433,7 +433,7 @@
 	/* invalidate existing TLB entry for flash + promjet */
 	disable_tlb(flash_esel);
 
-	set_tlb(1, flashbase, flashbase,		/* tlb, epn, rpn */
+	set_tlb(1, flashbase, CONFIG_SYS_FLASH_BASE_PHYS,	/* tlb, epn, rpn */
 		MAS3_SX|MAS3_SW|MAS3_SR, MAS2_I|MAS2_G,	/* perms, wimge */
 		0, flash_esel, BOOKE_PAGESZ_256M, 1);	/* ts, esel, tsize, iprot */