libata: Make sure drivers/ata is a separate Kconfig menu

Noticed by Rafael J. Wysocki
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/Kconfig

+#
+# SATA/PATA driver configuration
+#
+
+menu "Serial ATA (prod) and Parallel ATA (experimental) drivers"
+	depends on SCSI
 
 config ATA
 	tristate "ATA device support"
@@ -138,3 +144,5 @@ config SATA_INTEL_COMBINED
 	depends on IDE=y && !BLK_DEV_IDE_SATA && (SATA_AHCI || ATA_PIIX)
 	default y
 
+endmenu
+