ata: Migrate CONFIG_SCSI_AHCI to Kconfig

And use 'imply' liberally.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
diff --git a/configs/ls1088aqds_qspi_defconfig b/configs/ls1088aqds_qspi_defconfig
index 58276f7..df5bdaf 100644
--- a/configs/ls1088aqds_qspi_defconfig
+++ b/configs/ls1088aqds_qspi_defconfig
@@ -21,6 +21,7 @@
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_DM=y
+CONFIG_SCSI_AHCI=y
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_SPANSION=y