uqmi: fix raw-ip mode for newer lte modems

uqmi: fix raw-ip mode for newer lte modems

Some newer LTE modems, like the MC7455 or EC25-E do not support
"802.3" mode, and will stay in "raw-ip" regardless of the mode being
set.

In this case, the driver must be informed that it should handle all
packets in raw mode. [1]

This commit fixes connectivity issues for these devices.

Before:

[ Node 5 ] udhcpc -i wwan0
udhcpc: started, v1.27.2
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover

After:

[ Node 5 ] udhcpc -i wwan0
udhcpc: started, v1.27.2
udhcpc: sending discover
udhcpc: sending select for 100.66.245.226
udhcpc: lease of 100.66.245.226 obtained, lease time 7200
udhcpc: ifconfig wwan0 100.66.245.226 netmask 255.255.255.252 broadcast
+
udhcpc: setting default routers: 100.66.245.225

[1] https://lists.freedesktop.org/archives/libqmi-
devel/2017-January/002064.html

Tested on cns3xxx using a Sierra Wireless MC7455 LTE-A

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
[bumped PKG_RELEASE]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>