powerpc: mpc83xx: Enable pre-relocation malloc

To enable DM on MPC83xx, we need pre-relocation malloc, which is
implemented in this patch.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
[York S: Fixed compiling warning for unused variable 'i']
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc83xx/spl_minimal.c b/arch/powerpc/cpu/mpc83xx/spl_minimal.c
index 845861e..1c65e4c 100644
--- a/arch/powerpc/cpu/mpc83xx/spl_minimal.c
+++ b/arch/powerpc/cpu/mpc83xx/spl_minimal.c
@@ -18,14 +18,10 @@
  */
 void cpu_init_f (volatile immap_t * im)
 {
-	int i;
-
 	/* Pointer is writable since we allocated a register for it */
 	gd = (gd_t *) (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET);
 
-	/* Clear initial global data */
-	for (i = 0; i < sizeof(gd_t); i++)
-		((char *)gd)[i] = 0;
+	/* global data region was cleared in start.S */
 
 	/* system performance tweaking */