minui: convert ev_*() event interface to epoll

Help enable external main loop combined with ev_*() key event processing.

Specify EPOLLWAKEUP to hold a wakelock on any event, assuming this is needed
(may need to make this optional).

Convert callback events parameter to unsigned int.

Change-Id: Ib5e09abbd7724ffd830e2cf8e25e7eb59d3aa072
diff --git a/minui/minui.h b/minui/minui.h
index 1b8dd05..805c58b 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -50,7 +50,7 @@
 // see http://www.mjmwired.net/kernel/Documentation/input/ for info.
 struct input_event;
 
-typedef int (*ev_callback)(int fd, short revents, void *data);
+typedef int (*ev_callback)(int fd, unsigned int epevents, void *data);
 typedef int (*ev_set_key_callback)(int code, int value, void *data);
 
 int ev_init(ev_callback input_cb, void *data);
@@ -65,7 +65,7 @@
  */
 int ev_wait(int timeout);
 
-int ev_get_input(int fd, short revents, struct input_event *ev);
+int ev_get_input(int fd, unsigned int epevents, struct input_event *ev);
 void ev_dispatch(void);
 
 // Resources