Add SSSE3 implementation for ipred_cfl, ipred_cfl_top, ipred_cfl_left and ipred_cfl_128

cfl_pred_cfl_128_w4_8bpc_c: 291.3
cfl_pred_cfl_128_w4_8bpc_ssse3: 34.2
cfl_pred_cfl_128_w8_8bpc_c: 838.8
cfl_pred_cfl_128_w8_8bpc_ssse3: 55.4
cfl_pred_cfl_128_w16_8bpc_c: 1640.6
cfl_pred_cfl_128_w16_8bpc_ssse3: 91.8
cfl_pred_cfl_128_w32_8bpc_c: 4073.5
cfl_pred_cfl_128_w32_8bpc_ssse3: 206.6
cfl_pred_cfl_left_w4_8bpc_c: 321.6
cfl_pred_cfl_left_w4_8bpc_ssse3: 40.0
cfl_pred_cfl_left_w8_8bpc_c: 887.8
cfl_pred_cfl_left_w8_8bpc_ssse3: 62.9
cfl_pred_cfl_left_w16_8bpc_c: 1932.6
cfl_pred_cfl_left_w16_8bpc_ssse3: 97.4
cfl_pred_cfl_left_w32_8bpc_c: 4795.4
cfl_pred_cfl_left_w32_8bpc_ssse3: 213.8
cfl_pred_cfl_top_w4_8bpc_c: 359.7
cfl_pred_cfl_top_w4_8bpc_ssse3: 38.2
cfl_pred_cfl_top_w8_8bpc_c: 1007.1
cfl_pred_cfl_top_w8_8bpc_ssse3: 58.5
cfl_pred_cfl_top_w16_8bpc_c: 1873.4
cfl_pred_cfl_top_w16_8bpc_ssse3: 97.9
cfl_pred_cfl_top_w32_8bpc_c: 4523.7
cfl_pred_cfl_top_w32_8bpc_ssse3: 216.9
cfl_pred_cfl_w4_8bpc_c: 537.4
cfl_pred_cfl_w4_8bpc_ssse3: 44.9
cfl_pred_cfl_w8_8bpc_c: 1031.1
cfl_pred_cfl_w8_8bpc_ssse3: 66.7
cfl_pred_cfl_w16_8bpc_c: 1751.5
cfl_pred_cfl_w16_8bpc_ssse3: 99.9
cfl_pred_cfl_w32_8bpc_c: 4814.5
cfl_pred_cfl_w32_8bpc_ssse3: 219.8