This patch enables building SPL without
CONFIG_SPL_SERIAL_SUPPORT support.

Signed-off-by: Heiko Schocher <hs@denx.de>
[trini: Ensure we build arch/arm/imx-common on mx28]
Signed-off-by: Tom Rini <trini@konsulko.com>

This code is only used by one board, so it seems a shame to clutter up
the readline code with it. Move it into its own file.

Signed-off-by: Simon Glass <sjg@chromium.org>

This makes it clear where the code resides.

Signed-off-by: Simon Glass <sjg@chromium.org>

It doesn't make sense to have the simple parser and the readline code
all in main. Split them out into separate files.

Signed-off-by: Simon Glass <sjg@chromium.org>