ata: CONFIG_ATA is libata

Let users know that CONFIG_ATA is the kconfig symbol for libata,
since libata is mentioned in documentation and messages several
times.

Also correct a grammar typo.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NTejun Heo <tj@kernel.org>

drivers/ata/Kconfig

@@ -11,13 +11,13 @@ config HAVE_PATA_PLATFORM
 	  to update the PATA_PLATFORM entry.
 
 menuconfig ATA
-	tristate "Serial ATA and Parallel ATA drivers"
+	tristate "Serial ATA and Parallel ATA drivers (libata)"
 	depends on HAS_IOMEM
 	depends on BLOCK
 	depends on !(M32R || M68K || S390) || BROKEN
 	select SCSI
 	---help---
-	  If you want to use a ATA hard disk, ATA tape drive, ATA CD-ROM or
+	  If you want to use an ATA hard disk, ATA tape drive, ATA CD-ROM or
 	  any other ATA device under Linux, say Y and make sure that you know
 	  the name of your ATA host adapter (the card inside your computer
 	  that "speaks" the ATA protocol, also called ATA controller),