drm/i915: Report aliasing ppgtt size as ggtt size

The aliasing-ppgtt is constrained to be the same size as the Global GTT
since it aliases the same address space. Simplifying gtt size reporting
in this case.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190902040303.14195-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/i915_gem_context.c

@@ -2231,8 +2231,6 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
 		args->size = 0;
 		if (ctx->vm)
 			args->value = ctx->vm->total;
-		else if (to_i915(dev)->ggtt.alias)
-			args->value = to_i915(dev)->ggtt.alias->vm.total;
 		else
 			args->value = to_i915(dev)->ggtt.vm.total;
 		break;