noop: consolidate C sources list into Makefile.sources

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
diff --git a/configure.ac b/configure.ac
index f88a0ee..899f20f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2007,6 +2007,7 @@
 		src/gallium/drivers/identity/Makefile
 		src/gallium/drivers/ilo/Makefile
 		src/gallium/drivers/llvmpipe/Makefile
+		src/gallium/drivers/noop/Makefile
 		src/gallium/drivers/nouveau/Makefile
 		src/gallium/drivers/r300/Makefile
 		src/gallium/drivers/r600/Makefile