usb: musb: Add quirk to avoid skb reserve in gadget mode

For tusb6010 the DMA functionality only possible if the buffer is 32bit
aligned (SYNC access to FIFO) since with ASYNC access the TX/RX offset
registers will corrupt eventually.
The MUSB_G_NO_SKB_RESERVE will set the quirk_avoids_skb_reserve flag in
usb_gadget struct to provide correctly aligned buffer.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>