Add automake magic required for libobj/

So libobj/ wasn't included in the tarball, and nor was the compatability
functions being added to the driver when they were needed. The oddity is
that using the ./configure script (and thus make distcheck) succeeds. It
was only when 'autoreconf -fi' was run was the first error encoutered.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Tobias Klausmann

libobj/Makefile.am

@@ -0,0 +1,3 @@
+noinst_LTLIBRARIES = libcompat.la
+libcompat_la_SOURCES = ignore.c # for portability, always build something
+libcompat_la_LIBADD = $(LIBOBJS) $(ALLOCA)

libobj/ignore.c

@@ -0,0 +1,6 @@
+extern void ignore(void);
+
+void ignore(void)
+{
+	/* libcompat.a cannot be empty therefore I exist */
+}