vp8enc: modify the layerID setting
vp8enc: modify the layerID setting

According to libva, layer_id[] specifies the layer ids
for frames starting from the 2nd frame.

Signed-off-by: dongping wu <eada3ae4a96a673269eca90300aaefadacf3db15@intel.com>

stripes416/libyami,01org/libyami,YuJiankang/libyami,YuJiankang/libyami,01org/libyami,stripes416/libyami,stripes416/libyami,01org/libyami,YuJiankang/libyami