Adding function pointer type & array definition for luma vsp filter functions.
Adding C primitive for luma vsp filter functions.
Adding test bench code for luma vsp filter functions.
added  blockcopy_ps c primitive and function pointes
unit test code for block_copy_ps function
asm code for blockcopy_ps_8x2
asm code for blockcopy_ps_8x4
re-enable asm code for pixel_avg, the problem is miss EMMS
bugfix: PixelHarness::check_pixelavg_pp() output buffer did not initialize