Enhanced JPEG VA test app

Added support for YUV422, YUV444 and YUV420 and multi-scan images.

Changes
1. Added new functions for finding the start of image and end of image.
   This will be called while parsing the JIFF. This helps to detect
   the next image. The check for the bogus image format is removed as it
   is no longer valid with these new functions.
2. Since different images in the file has different width and height.
   The height and width will be stored in an array. These array variables
   will be passed while creating surfaces and contexts.
3. Added code to determine the format of the image from the h_sampling factor
   and v_sampling factor. This helps to support
   different image formats.

(cherry picked from commit ef53340b19746589079d7ed5f9c67970fcc40401)
2 files changed