Bug report: ip_handler_compute_ipv4_checksum only supports 512-bit bus width

[Frak8]

Describe the bug
When compiling with a data width smaller than 512 (e.g. using -DFNS_DATA_WIDTH=8, 16, 32, 64, 128), synthesis fails with the following error:

ERROR: [HLS 207-3339] no matching function for call to 'ip_handler_compute_ipv4_checksum' candidate function not viable: no known conversion from 'hls::stream<net_axis<128> >' to 'hls::stream<net_axis<512> > &' for 1st argument

This happens because the function ip_handler_compute_ipv4_checksum is currently declared as:

void ip_handler_compute_ipv4_checksum( hls::stream<net_axis<512>>& dataIn, hls::stream<net_axis<512>>& dataOut, hls::stream<subSums<32>>& subSumFiFoOut, const bool skipChecksum);