qmi_wwan: Add support for Dell Wireless 5809e 4G Modem

Added the USB IDs 0x413c:0x81b1 for the "Dell Wireless 5809e Gobi(TM) 4G
LTE Mobile Broadband Card", a Dell-branded Sierra Wireless EM7305 LTE
card in M.2 form factor, used eg. in Dell's Latitude E7540 Notebook
series.

Signed-off-by: Pieter Hollants <pieter@hollants.com>
Signed-off-by: David S. Miller <davem@davemloft.net>