firmware: arm_scmi: Allow PINCTRL_REQUEST to return EOPNOTSUPP

The SCMI protocol specification says that the PINCTRL_REQUEST and
PINCTRL_RELEASE commands are optional.  So if the SCMI server returns
-EOPNOTSUPP, then treat that as success and continue.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Sudeep Holla <sudeep.holla@kernel.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>

Author: Dan Carpenter

drivers/firmware/arm_scmi/pinctrl.c

@@ -578,6 +578,8 @@ static int scmi_pinctrl_request_free(const struct scmi_protocol_handle *ph,
 	tx->flags = cpu_to_le32(type);
 
 	ret = ph->xops->do_xfer(ph, t);
+	if (ret == -EOPNOTSUPP)
+		ret = 0;
 	ph->xops->xfer_put(ph, t);
 
 	return ret;