USB: serial: sierra: unify quirk handling logic

The sierra driver had two different functions for trying to determine
different quirks that did the same exact thing.  Remove one and rename
things to make it more obvious exactly what the different lists do.

Cc: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20200618094300.1887727-6-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>