Bluetooth: qca: fix NV variant for one of WCN3950 SoCs

The QCA_WCN3950_SOC_ID_S should be using qca/cmnv13s.bin, rather than
qca/cmnv13u.bin file. Correct the variant suffix to be used for this SoC
ID.

Fixes: d5712c51 ("Bluetooth: qca: add WCN3950 support")
Reported-by: Wojciech Slenska <wsl@trackunit.com>
Closes: https://github.com/qualcomm-linux/meta-qcom/pull/817#discussion_r2022866431


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>