ata: Migrate CONFIG_SCSI_AHCI to Kconfig

And use 'imply' liberally.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
diff --git a/configs/controlcenterdc_defconfig b/configs/controlcenterdc_defconfig
index f65e525..856591e 100644
--- a/configs/controlcenterdc_defconfig
+++ b/configs/controlcenterdc_defconfig
@@ -35,6 +35,7 @@
 CONFIG_OF_BOARD_FIXUP=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_SPL_OF_TRANSLATE=y
+CONFIG_SCSI_AHCI=y
 CONFIG_DM_GPIO=y
 CONFIG_DM_PCA953X=y
 CONFIG_DM_I2C=y