egl: update headers from registry

Khronos introduced a new macro (suggested by Google) to avoid using
C-style casts in C++ code, as those generate warnings.

Khronos Bugzilla: https://cvs.khronos.org/bugzilla/show_bug.cgi?id=16113
Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Chad Versace <chadversary@chromium.org>

include/EGL/eglplatform.h

@@ -2,7 +2,7 @@
 #define __eglplatform_h_
 
 /*
-** Copyright (c) 2007-2013 The Khronos Group Inc.
+** Copyright (c) 2007-2016 The Khronos Group Inc.
 **
 ** Permission is hereby granted, free of charge, to any person obtaining a
 ** copy of this software and/or associated documentation files (the
@@ -150,4 +150,12 @@ typedef EGLNativeWindowType  NativeWindowType;
  */
 typedef khronos_int32_t EGLint;
 
+
+/* C++ / C typecast macros for special EGL handle values */
+#if defined(__cplusplus)
+#define EGL_CAST(type, value) (static_cast<type>(value))
+#else
+#define EGL_CAST(type, value) ((type) (value))
+#endif
+
 #endif /* __eglplatform_h */