Fix typo in comments introduced by:
commit 
6dece0eb69b2a28e18d104bc5d707f1cb673f5e0
Author: Scott Wood <scottwood@freescale.com>
Date:   Mon Jul 25 11:29:33 2011 +0000
    powerpc/32: Pass device tree address as u64 to machine_init
Signed-off-by: Matthew McClintock <msm@freescale.com>
cc: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
        slw     r18,r18,r17             /* r18 = page size */
        addi    r18,r18,-1
        and     r19,r3,r18              /* r19 = page offset */
-       andc    r31,r20,r18             /* r3 = page base */
-       or      r31,r31,r19             /* r3 = devtree phys addr */
+       andc    r31,r20,r18             /* r31 = page base */
+       or      r31,r31,r19             /* r31 = devtree phys addr */
        mfspr   r30,SPRN_MAS7
 
        li      r25,0                   /* phys kernel start (low) */