ATA Disk Support: Add support for native ATA type drives ...

This changed patch removes more of the u-boot like code and replace it with
kernel like code.

commit 2a89669
Author: Juergen Beisert <jbe@pengutronix.de>
Date:   Fri Sep 30 15:06:26 2011 +0200

    ATA Disk Support: Add support for native ATA type drives

    Signed-off-by: Juergen Beisert <jbe@pengutronix.de>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>