igt: Trim timeouts for basic GEM tests

It's a compromise between detecting an unlikely timing error in one
test and being able to run a broader selection of tests. I hope this is
wise.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/tests/gem_exec_nop.c b/tests/gem_exec_nop.c
index f49d7d4..56298e1 100644
--- a/tests/gem_exec_nop.c
+++ b/tests/gem_exec_nop.c
@@ -315,10 +315,10 @@
 	}
 
 	igt_subtest("basic-series")
-		series(device, handle, 10);
+		series(device, handle, 5);
 
 	igt_subtest("basic-parallel")
-		parallel(device, handle, 10);
+		parallel(device, handle, 5);
 
 	for (e = intel_execution_engines; e->name; e++)
 		igt_subtest_f("%s", e->name)