Fix source for ECM error IVPR

The source vector for the ECM was being set to 2,
but that's what the source vector for DDR was being
set to.  Change it to 1.

Signed-off-by: Andy Fleming <afleming@freescale.com>

cpu/mpc85xx/interrupts.c

@@ -91,7 +91,7 @@ int interrupt_init (void)
 	set_msr (get_msr () | MSR_EE);
 
 #ifdef CONFIG_INTERRUPTS
-	pic->iivpr1 = 0x810002;	/* 50220 enable ecm interrupts */
+	pic->iivpr1 = 0x810001;	/* 50220 enable ecm interrupts */
 	debug("iivpr1@%x = %x\n",&pic->iivpr1, pic->iivpr1);
 
 	pic->iivpr2 = 0x810002;	/* 50240 enable ddr interrupts */