riscv64/cdef: filter functions

Benchmarks:

Kendryte K230

Banana PI BPI-F3

cdef_filter_4x4_01_8bpc_c: 1339.4 ( 1.00x) cdef_filter_4x4_01_8bpc_rvv: 836.2 ( 1.60x) cdef_filter_4x4_01_16bpc_c: 1369.1 ( 1.00x) cdef_filter_4x4_01_16bpc_rvv: 824.7 ( 1.66x) cdef_filter_4x4_10_8bpc_c: 872.8 ( 1.00x) cdef_filter_4x4_10_8bpc_rvv: 523.9 ( 1.67x) cdef_filter_4x4_10_16bpc_c: 938.2 ( 1.00x) cdef_filter_4x4_10_16bpc_rvv: 517.1 ( 1.81x) cdef_filter_4x4_11_8bpc_c: 2668.3 ( 1.00x) cdef_filter_4x4_11_8bpc_rvv: 1285.0 ( 2.08x) cdef_filter_4x4_11_16bpc_c: 2922.1 ( 1.00x) cdef_filter_4x4_11_16bpc_rvv: 1291.0 ( 2.26x) cdef_filter_4x8_01_8bpc_c: 2489.1 ( 1.00x) cdef_filter_4x8_01_8bpc_rvv: 1594.3 ( 1.56x) cdef_filter_4x8_01_16bpc_c: 2528.1 ( 1.00x) cdef_filter_4x8_01_16bpc_rvv: 1566.6 ( 1.61x) cdef_filter_4x8_10_8bpc_c: 1576.9 ( 1.00x) cdef_filter_4x8_10_8bpc_rvv: 967.1 ( 1.63x) cdef_filter_4x8_10_16bpc_c: 1641.3 ( 1.00x) cdef_filter_4x8_10_16bpc_rvv: 947.1 ( 1.73x) cdef_filter_4x8_11_8bpc_c: 5164.0 ( 1.00x) cdef_filter_4x8_11_8bpc_rvv: 2490.7 ( 2.07x) cdef_filter_4x8_11_16bpc_c: 5732.3 ( 1.00x) cdef_filter_4x8_11_16bpc_rvv: 2499.2 ( 2.29x) cdef_filter_8x8_01_8bpc_c: 4742.3 ( 1.00x) cdef_filter_8x8_01_8bpc_rvv: 1628.6 ( 2.91x) cdef_filter_8x8_01_16bpc_c: 4785.0 ( 1.00x) cdef_filter_8x8_01_16bpc_rvv: 1595.5 ( 3.00x) cdef_filter_8x8_10_8bpc_c: 2962.4 ( 1.00x) cdef_filter_8x8_10_8bpc_rvv: 1000.8 ( 2.96x) cdef_filter_8x8_10_16bpc_c: 3022.4 ( 1.00x) cdef_filter_8x8_10_16bpc_rvv: 975.7 ( 3.10x) cdef_filter_8x8_11_8bpc_c: 12623.9 ( 1.00x) cdef_filter_8x8_11_8bpc_rvv: 2525.4 ( 5.00x) cdef_filter_8x8_11_16bpc_c: 12470.7 ( 1.00x) cdef_filter_8x8_11_16bpc_rvv: 2528.2 ( 4.93x)

cdef_filter_4x4_01_8bpc_c: 1281.2 ( 1.00x) cdef_filter_4x4_01_8bpc_rvv: 813.0 ( 1.58x) cdef_filter_4x4_01_16bpc_c: 1300.8 ( 1.00x) cdef_filter_4x4_01_16bpc_rvv: 808.9 ( 1.61x) cdef_filter_4x4_10_8bpc_c: 843.0 ( 1.00x) cdef_filter_4x4_10_8bpc_rvv: 498.4 ( 1.69x) cdef_filter_4x4_10_16bpc_c: 903.6 ( 1.00x) cdef_filter_4x4_10_16bpc_rvv: 497.9 ( 1.81x) cdef_filter_4x4_11_8bpc_c: 2614.1 ( 1.00x) cdef_filter_4x4_11_8bpc_rvv: 1219.6 ( 2.14x) cdef_filter_4x4_11_16bpc_c: 2795.6 ( 1.00x) cdef_filter_4x4_11_16bpc_rvv: 1243.1 ( 2.25x) cdef_filter_4x8_01_8bpc_c: 2405.4 ( 1.00x) cdef_filter_4x8_01_8bpc_rvv: 1548.5 ( 1.55x) cdef_filter_4x8_01_16bpc_c: 2402.7 ( 1.00x) cdef_filter_4x8_01_16bpc_rvv: 1542.7 ( 1.56x) cdef_filter_4x8_10_8bpc_c: 1522.0 ( 1.00x) cdef_filter_4x8_10_8bpc_rvv: 917.4 ( 1.66x) cdef_filter_4x8_10_16bpc_c: 1589.2 ( 1.00x) cdef_filter_4x8_10_16bpc_rvv: 915.9 ( 1.74x) cdef_filter_4x8_11_8bpc_c: 5050.7 ( 1.00x) cdef_filter_4x8_11_8bpc_rvv: 2358.7 ( 2.14x) cdef_filter_4x8_11_16bpc_c: 5510.5 ( 1.00x) cdef_filter_4x8_11_16bpc_rvv: 2411.6 ( 2.28x) cdef_filter_8x8_01_8bpc_c: 4558.3 ( 1.00x) cdef_filter_8x8_01_8bpc_rvv: 1579.7 ( 2.89x) cdef_filter_8x8_01_16bpc_c: 4551.1 ( 1.00x) cdef_filter_8x8_01_16bpc_rvv: 1571.1 ( 2.90x) cdef_filter_8x8_10_8bpc_c: 2869.3 ( 1.00x) cdef_filter_8x8_10_8bpc_rvv: 948.4 ( 3.03x) cdef_filter_8x8_10_16bpc_c: 2928.6 ( 1.00x) cdef_filter_8x8_10_16bpc_rvv: 944.2 ( 3.10x) cdef_filter_8x8_11_8bpc_c: 12317.5 ( 1.00x) cdef_filter_8x8_11_8bpc_rvv: 2389.7 ( 5.15x) cdef_filter_8x8_11_16bpc_c: 11950.6 ( 1.00x) cdef_filter_8x8_11_16bpc_rvv: 2440.1 ( 4.90x)