libs: video-format: Improve the video format mapping.
The format mapping between GstVideoFormat and VAImageFormat have following problems:
- Use G_BYTE_ORDER to judge the VA_MSB_FIRST or VA_LSB_FIRST. The G_BYTE_ORDER is defined by glib and is the result of CPU platform. That does not mean all devices using VA interfaces need to be the same byte order.
- There are channels reorder between LSB and MSB. Gstreamer always define video format in MSB, need to re-order the channels if VA driver is LSB.
We modify it to generate a dynamically runtime video format map, consider both LSB and MSB drivers. Also consider driver special formats.