drm/i915/execlists: Assign virtual_engine->uncore from first sibling

Copy across the engine->uncore shortcut to the virtual_engine from its
first physical engine, similar to the handling of the engine->gt
backpointer.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008070342.4045-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_lrc.c

@@ -4170,6 +4170,7 @@ intel_execlists_create_virtual(struct i915_gem_context *ctx,
 
 	ve->base.i915 = ctx->i915;
 	ve->base.gt = siblings[0]->gt;
+	ve->base.uncore = siblings[0]->uncore;
 	ve->base.id = -1;
 	ve->base.class = OTHER_CLASS;
 	ve->base.uabi_class = I915_ENGINE_CLASS_INVALID;