Stop using immap_t for cpm offset on 85xx

In the future the offsets to various blocks may not be in same location.
Move to using CFG_MPC85xx_CPM_ADDR as the base of the CPM registers
instead of getting it via &immap->im_cpm.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/cpu/mpc85xx/speed.c b/cpu/mpc85xx/speed.c
index 5c35d4a..293269c 100644
--- a/cpu/mpc85xx/speed.c
+++ b/cpu/mpc85xx/speed.c
@@ -55,12 +55,12 @@
 {
 	sys_info_t sys_info;
 #if defined(CONFIG_CPM2)
-	volatile immap_t *immap = (immap_t *) CFG_IMMR;
+	volatile ccsr_cpm_t *cpm = (ccsr_cpm_t *)CFG_MPC85xx_CPM_ADDR;
 	uint sccr, dfbrg;
 
 	/* set VCO = 4 * BRG */
-	immap->im_cpm.im_cpm_intctl.sccr &= 0xfffffffc;
-	sccr = immap->im_cpm.im_cpm_intctl.sccr;
+	cpm->im_cpm_intctl.sccr &= 0xfffffffc;
+	sccr = cpm->im_cpm_intctl.sccr;
 	dfbrg = (sccr & SCCR_DFBRG_MSK) >> SCCR_DFBRG_SHIFT;
 #endif
 	get_sys_info (&sys_info);