drm/i915/gvt: refine trace_render_mmio

Refine trace_render_mmio to show the vm id before and after vgpu switch,
tag host id as '0', this patch will be used in the future patch for refine
mocs switch policy.

Signed-off-by: Weinan Li <weinan.z.li@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>