85xx: Introduce determine_mp_bootpg() helper.

Match determine_mp_bootpg() that was added for 86xx.  We need this to
address a bug introduced in v2009.03 with 86xx MP booting.  We have to
make sure to reserve the region of memory used for the MP bootpg() so
other u-boot code doesn't use it.

Also added a comment about how cpu_reset() is dealing w/an errata on
early 85xx MP HW.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/cpu/mpc85xx/mp.h b/cpu/mpc85xx/mp.h
index 4329286..2c2929e 100644
--- a/cpu/mpc85xx/mp.h
+++ b/cpu/mpc85xx/mp.h
@@ -1,10 +1,10 @@
 #ifndef __MPC85XX_MP_H_
 #define __MPC85XX_MP_H_
 
+#include <asm/mp.h>
+
 ulong get_spin_addr(void);
-void setup_mp(void);
 u32 get_my_id(void);
-void cpu_mp_lmb_reserve(struct lmb *lmb);
 
 #define BOOT_ENTRY_ADDR_UPPER	0
 #define BOOT_ENTRY_ADDR_LOWER	1