minui: Export minui/minui.h.

For libminui static and shared libraries.

Test: build
Change-Id: Ib30dc5e2ef4a3c8b3ca3a0cec68cb65e229a0c16
diff --git a/minui/events.cpp b/minui/events.cpp
index e6e7bd2..237af1c 100644
--- a/minui/events.cpp
+++ b/minui/events.cpp
@@ -25,7 +25,7 @@
 
 #include <linux/input.h>
 
-#include "minui.h"
+#include "minui/minui.h"
 
 #define MAX_DEVICES 16
 #define MAX_MISC_FDS 16