Add host events for shutdown due to thermal or battery

BUG=chrome-os-partner:12353
TEST=hack the thermal monitoring and/or battery code to trigger a shutdown
then see that the events get set

Change-Id: I5ef2ac03cdd793ab0c50c0db518cba1ede3ea036
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/29429
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

common/charge_state.c

@@ -105,6 +105,7 @@ static void poweroff_wait_ac(void)
 		 */
 #ifdef CONFIG_TASK_X86POWER
 		x86_power_force_shutdown();
+		host_set_single_event(EC_HOST_EVENT_BATTERY_SHUTDOWN);
 #endif /* CONFIG_TASK_X86POWER */
 	}
 }

common/thermal.c

@@ -110,6 +110,7 @@ static void overheated_action(void)
 		cprintf(CC_CHIPSET,
 			"[%T critical temperature; shutting down]\n");
 		x86_power_force_shutdown();
+		host_set_single_event(EC_HOST_EVENT_THERMAL_SHUTDOWN);
 		return;
 	}
 

common/x86_power.c

@@ -193,6 +193,7 @@ void x86_power_cpu_overheated(int too_hot)
 		if (overheat_count > 3) {
 			CPRINTF("[%T overheated; shutting down]\n");
 			x86_power_force_shutdown();
+			host_set_single_event(EC_HOST_EVENT_THERMAL_SHUTDOWN);
 		}
 	} else {
 		overheat_count = 0;

include/ec_commands.h

@@ -217,6 +217,12 @@ enum host_event_code {
 	EC_HOST_EVENT_INTERFACE_READY = 14,
 	/* Keyboard recovery combo has been pressed */
 	EC_HOST_EVENT_KEYBOARD_RECOVERY = 15,
+
+	/* Shutdown due to thermal overload */
+	EC_HOST_EVENT_THERMAL_SHUTDOWN = 16,
+	/* Shutdown due to battery level too low */
+	EC_HOST_EVENT_BATTERY_SHUTDOWN = 17,
+
 	/*
 	 * The high bit of the event mask is not used as a host event code.  If
 	 * it reads back as set, then the entire event mask should be