found via `codespell-q 3`
please review

Github issue 162, by rcdaily).

NEON support is provided by filter_neon.S which is currently not build
by cmake causing an error when linking with libpng16.so.16.32.0:

[ 97%] Linking C executable pngstest
libpng16.so.16.32.0: undefined reference to `png_read_filter_row_avg4_neon'
libpng16.so.16.32.0: undefined reference to `png_read_filter_row_paeth3_neon'
libpng16.so.16.32.0: undefined reference to `png_read_filter_row_up_neon'
libpng16.so.16.32.0: undefined reference to `png_read_filter_row_avg3_neon'
libpng16.so.16.32.0: undefined reference to `png_read_filter_row_paeth4_neon'
libpng16.so.16.32.0: undefined reference to `png_read_filter_row_sub4_neon'
libpng16.so.16.32.0: undefined reference to `png_read_filter_row_sub3_neon'

no longer using deprecated cmake LOCATION feature (Clifford Yapp).