button-hotplug: Add KEY_POWER handling

When running OpenWrt within KVM KEY_POWER is generated from the ACPI
button driver when restarting or powering down the VM.

Extend button-hotplug to allow user space handlers for these events.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Patchwork: http://patchwork.openwrt.org/patch/3799/

SVN-Revision: 37160

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

@@ -84,6 +84,7 @@ static struct bh_map button_map[] = {
 	BH_MAP(BTN_8,		"BTN_8"),
 	BH_MAP(BTN_9,		"BTN_9"),
 	BH_MAP(KEY_RESTART,	"reset"),
+	BH_MAP(KEY_POWER,	"power"),
 #ifdef KEY_WPS_BUTTON
 	BH_MAP(KEY_WPS_BUTTON,	"wps"),
 #endif /* KEY_WPS_BUTTON */