Fix the following W=1 kernel warnings:

drivers/gpu/drm/i915/gvt/handlers.c:3066: warning: expecting prototype
for intel_t_default_mmio_write(). Prototype was for
intel_vgpu_default_mmio_write() instead.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220524083733.67148-2-jiapeng.chong@linux.alibaba.comAcked-by: Zhenyu Wang <zhenyuw@linux.intel.com>