x86: adapt SSSE3 cdef_filter_{4x4,4x8,8x8} to SSE2
x86: adapt SSSE3 cdef_filter_{4x4,4x8,8x8} to SSE2

---------------------
x86_64:
------------------------------------------
cdef_filter_4x4_8bpc_c: 1376.0
cdef_filter_4x4_8bpc_sse2: 177.6
cdef_filter_4x4_8bpc_ssse3: 132.5
---------------------
cdef_filter_4x8_8bpc_c: 2725.0
cdef_filter_4x8_8bpc_sse2: 327.6
cdef_filter_4x8_8bpc_ssse3: 234.9
---------------------
cdef_filter_8x8_8bpc_c: 5938.8
cdef_filter_8x8_8bpc_sse2: 556.8
cdef_filter_8x8_8bpc_ssse3: 388.1
------------------------------------------

---------------------
x86_32:
------------------------------------------
cdef_filter_4x4_8bpc_c: 1569.5
cdef_filter_4x4_8bpc_sse2: 201.9
cdef_filter_4x4_8bpc_ssse3: 162.3
---------------------
cdef_filter_4x8_8bpc_c: 3141.6
cdef_filter_4x8_8bpc_sse2: 368.3
cdef_filter_4x8_8bpc_ssse3: 283.4
---------------------
cdef_filter_8x8_8bpc_c: 6534.5
cdef_filter_8x8_8bpc_sse2: 666.7
cdef_filter_8x8_8bpc_ssse3: 503.5
------------------------------------------

xiph/rav1e,xiph/rav1e