ata: Migrate CONFIG_DWC_AHSATA to Kconfig

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
diff --git a/configs/nitrogen6q_defconfig b/configs/nitrogen6q_defconfig
index 65d7591..bf12cbd 100644
--- a/configs/nitrogen6q_defconfig
+++ b/configs/nitrogen6q_defconfig
@@ -32,6 +32,7 @@
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
+CONFIG_DWC_AHSATA=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_SST=y
 CONFIG_PHYLIB=y