Add support for ahci on sysbus.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NMark Langsdorf <mark.langsdorf@calxeda.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>