i965: Add a dependency on libisl

To avoid build issues, ensure that you're running `make' at the top level
and/or you've executed `make clean' beforehand.

Reviewed-by: Chad Versace <chad.versace@intel.com>
diff --git a/src/Makefile.am b/src/Makefile.am
index a0572b7..1471fa0 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -24,10 +24,19 @@
 # include only conditionally ?
 SUBDIRS += compiler
 
+if HAVE_INTEL_DRIVERS
+SUBDIRS += intel
+endif
+
 if NEED_OPENGL_COMMON
 SUBDIRS += mesa
 endif
 
+# This explicitly comes after mesa because it depends on the i965 compiler
+if HAVE_INTEL_VULKAN
+SUBDIRS += intel/vulkan
+endif
+
 SUBDIRS += loader
 
 if HAVE_DRI_GLX
@@ -56,10 +65,6 @@
 AM_CFLAGS = $(VISIBILITY_CFLAGS)
 AM_CXXFLAGS = $(VISIBILITY_CXXFLAGS)
 
-if HAVE_INTEL_DRIVERS
-SUBDIRS += intel
-endif
-
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/include/ \
 	-I$(top_srcdir)/src/mapi/ \