ahci_sunxi: Add support for sunxi sata controller

Based on the AHCI SATA platform driver by Freescale and Allwinner
Based on code from
 Allwinner Technology Co., Ltd. <www.allwinnertech.com>
 Daniel Wang <danielwang@allwinnertech.com>

Signed-off-by: Oliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>