ADS5121 Add PATA support

Original patch from Ralph Kondziella
plus clean up by Wolfgang Denk
plus changes by John Rigby
    use ips clock not lpc
    port forward to current u-boot release

Signed-off-by: Ralph Kondziella <rk@argos-messtechnik.de>
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: John Rigby <jrigby@freescale.com>