Stop using immap_t for guts offset on 85xx

In the future the offsets to various blocks may not be in same location.
Move to using CFG_MPC85xx_GUTS_ADDR as the base of the guts registers
instead of getting it via &immap->im_gur.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/cpu/mpc85xx/pci.c b/cpu/mpc85xx/pci.c
index db09e45..35e96d9 100644
--- a/cpu/mpc85xx/pci.c
+++ b/cpu/mpc85xx/pci.c
@@ -48,7 +48,7 @@
 #ifdef CONFIG_MPC85XX_PCI2
 	volatile ccsr_pcix_t *pcix2 = &immap->im_pcix2;
 #endif
-	volatile ccsr_gur_t *gur = &immap->im_gur;
+	volatile ccsr_gur_t *gur = (void *)(CFG_MPC85xx_GUTS_ADDR);
 	struct pci_controller * hose;
 
 	pci_hose = board_hose;