platform/chrome: cros_ec_typec: Make try power role optional

Some boards prefer not to specify a try-power-role. Update the port
property parsing logic to not error out in case a try-power-role is not
specified.

Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/chrome-platform/20220127191659.3560810-1-pmalani@chromium.org/

drivers/platform/chrome/cros_ec_typec.c

@@ -115,17 +115,18 @@ static int cros_typec_parse_port_props(struct typec_capability *cap,
 		return ret;
 	cap->data = ret;
 
+	/* Try-power-role is optional. */
 	ret = fwnode_property_read_string(fwnode, "try-power-role", &buf);
 	if (ret) {
-		dev_err(dev, "try-power-role not found: %d\n", ret);
-		return ret;
+		dev_warn(dev, "try-power-role not found: %d\n", ret);
+		cap->prefer_role = TYPEC_NO_PREFERRED_ROLE;
+	} else {
+		ret = typec_find_power_role(buf);
+		if (ret < 0)
+			return ret;
+		cap->prefer_role = ret;
 	}
 
-	ret = typec_find_power_role(buf);
-	if (ret < 0)
-		return ret;
-	cap->prefer_role = ret;
-
 	cap->fwnode = fwnode;
 
 	return 0;