[PATCH] USB: usbnet (5/9) module for genesys gl620a cables

This moves the GeneSys GL620USB-A support into its own driver file.
It also fixes a "return wrong skb" glitch in the rx unbatching, as
recently reported, and adds some missing byteswaps in the special
"genelink" headers (so it might now work on big-endian Linux).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>