msm: mhi_dev: Checking the out channel status directly

If the net dev init process is scheduled out in between registering
a callback for in-channel and out-channel and start command for these
channels gets processed at this time (after registering the callback
for out channel but before registeringthe callback for in-channel)
then with existing logic, we never register with the network interface.

Checking the out channel status directly rather than using local bool
variable out_channel_started before calling
mhi_dev_net_open_chan_create_netif API. If out channel status is
connected the mhi_dev_net_open_chan_create_netif API is called.

Change-Id: I69af6c49ee565ffd04c4d0ac22b686ff986b7bc7
Signed-off-by: Sai Chaitanya Kaveti <quic_skaveti@quicinc.com>