[gtkglarea] Use AM_CPPFLAGS instead deprecated INCLUDES

[Javier Jardón <jjardon src gnome org>]

commit 5db9aae1894cd2912ea1df7280af86321a8a90d9
Author: Javier Jardón <jjardon gnome org>
Date:   Thu Feb 27 03:10:06 2014 +0000

    Use AM_CPPFLAGS instead deprecated INCLUDES

 examples/Makefile.am |    2 +-
 gtkgl/Makefile.am    |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 2c288a3..665d375 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -8,7 +8,7 @@ endif
 
 noinst_PROGRAMS = simple zktor viewlw glpixmap gdkfont $(shader_programs) gtkglarea_demo
 
-INCLUDES = -I$(top_srcdir)
+AM_CPPFLAGS = -I$(top_srcdir)
 LDADD = $(top_builddir)/gtkgl/libgtkgl-2.0.la $(GTK_LIBS) $(GL_LIBS) $(LIBM)
 
 simple_SOURCES   = simple.c
diff --git a/gtkgl/Makefile.am b/gtkgl/Makefile.am
index c7e65cd..a8c5011 100644
--- a/gtkgl/Makefile.am
+++ b/gtkgl/Makefile.am
@@ -27,8 +27,8 @@ endif
 
 EXTRA_DIST = makefile.mingw makefile.mingw.in gtkgl.def
 
+AM_CPPFLAGS = -I$(top_srcdir)
 AM_CFLAGS = $(GTK_CFLAGS) $(GL_CFLAGS)
-INCLUDES= -I$(top_srcdir)
 
 gtkglincludedir = $(includedir)/gtkgl-2.0/gtkgl