mesa: automake: include mesa_glinterop.h in distfile

Add mesa_glinterop.h to the list of headers that will get included
in the distfile as it is required to build Mesa itself.

Corrects a regression introduced in a89faa2022.

Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

src/Makefile.am

@@ -131,7 +131,8 @@ SUBDIRS += gallium
 endif
 
 EXTRA_DIST = \
-	getopt hgl SConscript
+	getopt hgl SConscript \
+	$(top_srcdir)/include/GL/mesa_glinterop.h
 
 AM_CFLAGS = $(VISIBILITY_CFLAGS)
 AM_CXXFLAGS = $(VISIBILITY_CXXFLAGS)