gpio-button-hotplug: add vendor button handling

Handle the KEY_VENDOR key in gpio-button-hotplug driver. This is used
by Turris Omnia.

Signed-off-by: Marek Behún <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/13799
Signed-off-by: Robert Marko <[email protected]>

package/kernel/gpio-button-hotplug/src/gpio-button-hotplug.c

@@ -100,6 +100,7 @@ static struct bh_map button_map[] = {
 	BH_MAP(KEY_WIMAX,		"wwan"),
 	BH_MAP(KEY_WLAN,		"wlan"),
 	BH_MAP(KEY_WPS_BUTTON,		"wps"),
+	BH_MAP(KEY_VENDOR,		"vendor"),
 };
 
 /* -------------------------------------------------------------------------*/