board_init_lowlevel is no longer called from generic code, so we can't
just return from in. Instead we have to jump to board_init_lowlevel_return
manually. For the a9m2440 board one case was missed to convert. This
is broken since:

| commit faf7b7a
| Author: Jan Luebbe <jlu@pengutronix.de>
| Date:   Mon Sep 24 10:18:34 2012 +0200
|
|     ARM: give boards control of the reset entry point
|
|     On some SoCs (for example AM35xx), the ROM bootloader passes useful
|     information in r0 when jumping to barebox.
|
|     To avoid overwriting this in the generic reset code, we introduce
|     common_reset as a C function and as an assembler macro. This is then
|     called form the reset entry point (either in common or in board code).
|
|     This patch is based on code by Sascha Hauer <s.hauer@pengutronix.de>.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>