drm/i915/selftest: also consider non-contiguous objects

In igt_ppgtt_sanity_check we should also exercise the non-contiguous
option for LMEM, since this will give us slightly different sg layouts
and alignment.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130141809.65330-1-matthew.auld@intel.com

drivers/gpu/drm/i915/gem/selftests/huge_pages.c

@@ -1333,6 +1333,7 @@ static int igt_ppgtt_sanity_check(void *arg)
 		unsigned int flags;
 	} backends[] = {
 		{ igt_create_system, 0,                        },
+		{ igt_create_local,  0,                        },
 		{ igt_create_local,  I915_BO_ALLOC_CONTIGUOUS, },
 	};
 	struct {