usb: dma bounce buffer support

usb: dma bounce buffer support V4

This patch adds dma bounce buffer support to the usb core. These buffers
can be enabled with the HCD_LOCAL_MEM flag, and they make sure that all data
passed to the host controller is allocated using dma_alloc_coherent().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 080298a..0095641 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -165,6 +165,7 @@
 
 	int	flags;
 #define	HCD_MEMORY	0x0001		/* HC regs use memory (else I/O) */
+#define	HCD_LOCAL_MEM	0x0002		/* HC needs local memory */
 #define	HCD_USB11	0x0010		/* USB 1.1 */
 #define	HCD_USB2	0x0020		/* USB 2.0 */