ARM: Kirkwood: ehci-orion: Add device tree binding

Based on previous work by Michael Walle and Jason Cooper.

Made their work actually work, which required added interrupt from DT
and auxdata, along with setting the dma_mask, which DT does not
currently do.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>