remoteproc: stm32: demote warning about optional property absence

The mainline device trees lack the "st,syscfg-pdds", so probing the
driver always throws the warning. As the property is optional per binding
and the driver can deal with its absence, demote the warning to info log
level.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/20200224172519.15315-1-a.fatoum@pengutronix.deSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/stm32_rproc.c

@@ -602,7 +602,7 @@ static int stm32_rproc_parse_dt(struct platform_device *pdev)
 
 	err = stm32_rproc_get_syscon(np, "st,syscfg-pdds", &ddata->pdds);
 	if (err)
-		dev_warn(dev, "failed to get pdds\n");
+		dev_info(dev, "failed to get pdds\n");
 
 	rproc->auto_boot = of_property_read_bool(np, "st,auto-boot");