sunxi: Implement poweroff support for axp221 pmic

Adds poweroff support for axp221 pmic.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/include/axp221.h b/include/axp221.h
index 0ee21b6..04cd8c2 100644
--- a/include/axp221.h
+++ b/include/axp221.h
@@ -45,6 +45,8 @@
 #define AXP221_ALDO3_CTRL	0x2a
 #define AXP221_VBUS_IPSOUT	0x30
 #define AXP221_VBUS_IPSOUT_DRIVEBUS	(1 << 2)
+#define AXP221_SHUTDOWN		0x32
+#define AXP221_SHUTDOWN_POWEROFF	(1 << 7)
 #define AXP221_MISC_CTRL	0x8f
 #define AXP221_MISC_CTRL_N_VBUSEN_FUNC	(1 << 4)
 #define AXP221_PAGE		0xff