video_info: normalize VideoBufferInfo and cl_image_info

 * VideoBufferInfo, add <init> to make format/width/height simple
 * add new fourcc for 16bits
       XCAM_PIX_FMT_RGBA64,  rgba with each channel 16 bits
       XCAM_PIX_FMT_RGB48,   rgb with each channel 16 bits
       XCAM_PIX_FMT_SGRBG16, grbg, with each channel 16 bits
 * CLVaImage, construction support most formats convert to cl_libva_image
       cl_image doesn't support XCAM_PIX_FMT_RGB48, consider later
5 files changed