contrib: aom: update to 3.8.2

• Bug Fixes
  • aomedia:3523: SIGFPE in av1_twopass_postencode_update() pass2_strategy.c:4261.
  • aomedia:3535, b/317646516: Over reads in aom_convolve_copy_neon().
  • aomedia:3543: invalid feature modifier when compiling aom_dsp/arm/aom_convolve8_neon_i8mm.c on Debian 10 with arm64 architecture.
  • aomedia:3545: Failed to parse configurations due to inconsistent elements between two arrays "av1_ctrl_args" and "av1_arg_ctrl_map" in aomenc.c.
  • oss-fuzz:66474, b/319140742: Integer-overflow in search_wiener.
  • Zero initialize an array in cdef search.

See: https://aomedia.googlesource.com/aom/+/refs/tags/v3.8.2