Due to USB controllers may have different restrictions, usb gadget layer
needs to provide a generic way to inform gadget functions to complain
with non-standard requirements.

This patch adds 'quirk_ep_out_aligned_size' field to struct usb_gadget
to inform when controller's epout requires buffer size to be aligned to
MaxPacketSize. A helper is also provided to align buffer size when
necessary.

Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NDavid Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>