usb: ohci-sm501 driver V2

This patch adds sm501 ohci support. It's all very straightforward with the
exception of dma_declare_coherent_memory() and HCD_LOCAL_MEM. Together they
are used to ensure that usb data is allocated using dma_alloc_coherent(),
and that only valid dma memory is used to allocate from. This driver is
a platform device, and the mfd driver sm501.c is already creating one
usb host controller instance per sm501.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>