[mutter] Fix out-of-tree building

[Jonas Ådahl <jadahl src gnome org>]

commit f18e2a8c31880ede4de1d9f81476cbeaf03b9bd3
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Jul 20 16:17:22 2016 +0800

    Fix out-of-tree building
    
    We included generated cogl headers and non-generated clutter headers
    from mutter, while only having added include paths for the opposite.

 src/Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 988227c..0a4d7c7 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -27,8 +27,10 @@ AM_CPPFLAGS = \
        -I$(top_srcdir)/cogl                                            \
        -I$(top_srcdir)/cogl/cogl                                       \
        -I$(top_srcdir)/cogl/cogl/winsys                                \
+       -I$(top_builddir)/cogl/cogl                                     \
        -I$(top_builddir)/cogl                                          \
        -I$(top_srcdir)/clutter                                         \
+       -I$(top_srcdir)/clutter/clutter                                 \
        -I$(top_builddir)/clutter                                       \
        -I$(top_builddir)/clutter/clutter                               \
        -DMUTTER_LIBEXECDIR=\"$(libexecdir)\"                           \