ata: Migrate CONFIG_SCSI_AHCI to Kconfig

And use 'imply' liberally.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
diff --git a/configs/MPC8610HPCD_defconfig b/configs/MPC8610HPCD_defconfig
index 40256c8..cb2e063 100644
--- a/configs/MPC8610HPCD_defconfig
+++ b/configs/MPC8610HPCD_defconfig
@@ -16,6 +16,7 @@
 CONFIG_CMD_BMP=y
 CONFIG_CMD_EXT2=y
 CONFIG_DOS_PARTITION=y
+CONFIG_SCSI_AHCI=y
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y
 CONFIG_SCSI=y