Nokia RX-51: Fix calculating return address in save_boot_params

Commit e11c6c27 broke calculating lr register
in function save_boot_params() and caused U-Boot to crash at early boot time
on Nokia N900 board.

This patch fix calculating return address in lr register and make Nokia N900
board bootable again. Patch was tested in qemu and also on real N900 HW.
Reviewed-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NPali Rohár <pali.rohar@gmail.com>

board/nokia/rx51/lowlevel_init.S

@@ -105,10 +105,6 @@ fix_start:
 	/* r6 - maximal u-boot size */
 	ldr	r6, imagesize
 
-	/* fix return address */
-	subhi	lr, lr, r5
-	addlo	lr, lr, r5
-
 	/* r1 - start of u-boot after */
 	ldr	r1, startaddr