sunxi: Use the available Kconfig option for AHCI

Use the already available Kconfig option for AHCI. Tested on the
BananaPi.

Signed-off-by: Jelle van der Waa <jelle@vdwaa.nl>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/configs/Wits_Pro_A20_DKT_defconfig b/configs/Wits_Pro_A20_DKT_defconfig
index d83cee7..d847fc7 100644
--- a/configs/Wits_Pro_A20_DKT_defconfig
+++ b/configs/Wits_Pro_A20_DKT_defconfig
@@ -11,7 +11,8 @@
 CONFIG_VIDEO_LCD_PANEL_LVDS=y
 CONFIG_DEFAULT_DEVICE_TREE="sun7i-a20-wits-pro-a20-dkt"
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
-CONFIG_SYS_EXTRA_OPTIONS="SUNXI_GMAC,RGMII,AHCI"
+CONFIG_AHCI=y
+CONFIG_SYS_EXTRA_OPTIONS="SUNXI_GMAC,RGMII"
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set