Controller locks up on some boards.

[MJoergen]

This is observed when connecting a PicoLemon HyperRAM module to the PMODs of a QMTech Wukong board.

I suspect the problem is due to the increased latency through the board traces and PMODs.

[AnttiLukats]

There is no significant routing latency, that is not the problem for sure.

[AnttiLukats]

The lock up is for sure the same issue as with mega65 R6, there is a BUG in hyperram_rx.vhd code, the code as is would lock up at first time when FIFO is empty! This is a real bug that is easy to fix.