Move input handling into the main thread

This also makes the hardwarekeyboard.cpp file that I created for
the Asus Transformer tablets with a keyboard dock the default
hardware keyboard handler. USB keyboards should work properly now
if present for keyboard input.

Change-Id: I724606e91ffe2a55265a9d1cb1ec714de244d38b
diff --git a/minuitwrp/minui.h b/minuitwrp/minui.h
index cb9f8a3..abebc14 100644
--- a/minuitwrp/minui.h
+++ b/minuitwrp/minui.h
@@ -75,7 +75,7 @@
 
 int ev_init(void);
 void ev_exit(void);
-int ev_get(struct input_event *ev, unsigned dont_wait);
+int ev_get(struct input_event *ev);
 int ev_has_mouse(void);
 
 // Resources