net: wwan: mhi_wwan_mbim: use correct mux_id for multiplexing

net: wwan: mhi_wwan_mbim: use correct mux_id for multiplexing

Recent Qualcomm chipsets like SDX72/75 require MBIM sessionId mapping
to muxId in the range (0x70-0x8F) for the PCIe tethered use.

This has been partially addressed by the referenced commit, mapping
the default data call to muxId = 112, but the multiplexed data calls
scenario was not properly considered, mapping sessionId = 1 to muxId
1, while it should have been 113.

Fix this by moving the session_id assignment logic to mhi_mbim_newlink,
in order to map sessionId = n to muxId = n + WDS_BIND_MUX_DATA_PORT_MUX_ID.

Fixes: 65bc58c3dcad ("net: wwan: mhi: make default data link id configurable")
Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Reviewed-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Link: https://patch.msgid.link/20250603091204.2802840-1-dnlplm@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>