Add code for starting up U-Boot SPL and U-Boot proper. This is generic and
makes use of devices provided by the board- or SoC-specific code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add code to set up the SDRAM in SPL, ready for loading U-Boot. This uses
device tree for configuration so should be able to support other RAM
configurations. It may be possible to generalise the code to support other
SoCs at some point.
Signed-off-by: Simon Glass <sjg@chromium.org>