docs: networking: Update codeaurora references for rmnet

source.codeaurora.org is no longer accessible and so the reference link
in the documentation is not useful. Use iproute2 instead as it has a
rmnet module for configuration.

Fixes: ceed73a2 ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Sean Tranchetti <quic_stranche@quicinc.com>
Signed-off-by: Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst

@@ -190,8 +190,7 @@ MAP header|IP Packet|Optional padding|MAP header|Command Packet|Optional pad...
 3. Userspace configuration
 ==========================
 
-rmnet userspace configuration is done through netlink library librmnetctl
-and command line utility rmnetcli. Utility is hosted in codeaurora forum git.
-The driver uses rtnl_link_ops for communication.
+rmnet userspace configuration is done through netlink using iproute2
+https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/
 
-https://source.codeaurora.org/quic/la/platform/vendor/qcom-opensource/dataservices/tree/rmnetctl
+The driver uses rtnl_link_ops for communication.