usb: gadget: ether set wMaxPacketSize

usb: gadget: ether set wMaxPacketSize

set wMaxPacketSize for full speed descriptors
fs_source_desc, fs_sink_desc to 64.

Full-speed bulk endpoint can have a maximum packet size of
8, 16, 32, or 64 bytes, so choice 64.

The hs_source_desc, hs_sink_desc, already have their wMaxPacketSize
set to 512. That is the only legal value for high speed bulk endpoints.

Strictly speaking, this patch is not needed because
usb_ep_autoconfig will call ep_matches which will
override wMaxPacketSize for BULK endpoints only with
the size associated with the endpoint setup by the udc driver.
But if you want to rely on this, you may as well combine the
full speed descriptor with the high speed descriptor to
minimize confusion.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>