[libata] Add 460EX on-chip SATA driver, sata_dwc_460ex

This patch enables the on-chip DWC SATA controller of the AppliedMicro
processor 460EX.

Signed-off-by: Rupjyoti Sarmah <rsarmah@appliedmicro.com>
Signed-off-by: Mark Miesfeld <mmiesfeld@appliedmicro.com>
Signed-off-by: Prodyut Hazarika <phazarika@appliedmicro.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --cc drivers/ata/Kconfig
Simple merge

diff --cc drivers/ata/Makefile
Simple merge

diff --cc drivers/ata/sata_dwc_460ex.c
Simple merge