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: d5712c5 ("Bluetooth: qca: add WCN3950 support")
Reported-by: Wojciech Slenska <wsl@trackunit.com>
Closes: qualcomm-linux/meta-qcom#817 (comment)
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Author: lumag

drivers/bluetooth/btqca.c

@@ -889,7 +889,7 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
 			if (le32_to_cpu(ver.soc_id) == QCA_WCN3950_SOC_ID_T)
 				variant = "t";
 			else if (le32_to_cpu(ver.soc_id) == QCA_WCN3950_SOC_ID_S)
-				variant = "u";
+				variant = "s";
 
 			snprintf(config.fwname, sizeof(config.fwname),
 				 "qca/cmnv%02x%s.bin", rom_ver, variant);