NCM and MBIM can share most of the bind function.  Split
out the shareable part and add MBIM functional descriptor
parsing.
Signed-off-by: NGreg Suarez <gsuarez@smithmicro.com>
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>