recovery: Add wipe system partition option

Change-Id: Id606cef249a7464037443de6265055803c290d82
diff --git a/recovery_ui/device.cpp b/recovery_ui/device.cpp
index e09431a..c09411d 100644
--- a/recovery_ui/device.cpp
+++ b/recovery_ui/device.cpp
@@ -34,6 +34,7 @@
   { "Apply update from SD card", Device::APPLY_SDCARD },
   { "Wipe data/factory reset", Device::WIPE_DATA },
   { "Wipe cache partition", Device::WIPE_CACHE },
+  { "Wipe system partition", Device::WIPE_SYSTEM },
   { "Mount /system", Device::MOUNT_SYSTEM },
   { "View recovery logs", Device::VIEW_RECOVERY_LOGS },
   { "Run graphics test", Device::RUN_GRAPHICS_TEST },