ata: Migrate CONFIG_DWC_AHSATA to Kconfig

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
diff --git a/configs/cm_fx6_defconfig b/configs/cm_fx6_defconfig
index 0773aca..8e0746b 100644
--- a/configs/cm_fx6_defconfig
+++ b/configs/cm_fx6_defconfig
@@ -52,6 +52,7 @@
 CONFIG_MTDPARTS_DEFAULT="mtdparts=spi0.0:768k(uboot),256k(uboot-environment),-(reserved)"
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
+CONFIG_DWC_AHSATA=y
 CONFIG_DM_MMC=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_ATMEL=y