ata: add Atari Falcon PATA controller driver

Add Atari Falcon PATA controller driver.  The major difference
when compared to legacy IDE's falconide host driver is that we
are using polled PIO mode and thus avoiding the need for STDMA
locking magic altogether.

Tested under ARAnyM emulator.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>