USB: qcserial: add Sierra Wireless MC74xx/EM74xx

[ Upstream commit 34a251c6eecaaf5e863ed366089e7ac9a5b78986 ]

commit f504ab1888026d15b5be8f9c262bf4ae9cacd177 upstream.

New device IDs shamelessly lifted from the vendor driver.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>