Fix ff_bfin_yuv2rgb_get_func_ptr() vs. sws_ff_bfin_yuv2rgb_get_func_ptr() name

mismatch. The function is now called sws_yuv2rgb_get_func_ptr_bfin().

Originally committed as revision 28982 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale