[libata] Add Samsung PATA controller driver, pata_samsung_cf

Adds support for the Samsung PATA controller. This driver is based
on the Libata subsystem and references the earlier patches sent for
IDE subsystem.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: Sergei Shtylyov <sshtylyov@mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>