tests/gem_render_copy: Add a simple render copy test

The goal is here to both: demonstrate a simple usage of render copy with
the possibility to write pngs to visualize what it's doing and to
provide a test bed to port the render copy function to new
architectures.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>

tests/Makefile.am

@@ -88,6 +88,7 @@ TESTS_progs = \
 	gem_pin \
 	gem_pipe_control_store_loop \
 	gem_reg_read \
+	gem_render_copy \
 	gem_render_linear_blits \
 	gem_render_tiled_blits \
 	gem_ring_sync_loop \