avcodec/ppc/h264chroma_template: POWER LE support for PREFIX_h264_chroma_mc8_altivec() PREFIX_no_rnd_vc1_chroma_mc8_altivec() CHROMA_MC8_ALTIVEC_CORE_SIMPLE() CHROMA_MC8_ALTIVEC_CORE()

add marcos GET_VSRC1() GET_VSRC()
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>