Reset: suppress brief noise immediatly after power on
Reset: suppress brief noise immediatly after power on

A noise with a duration of the first video frame snuck in.
Caused by increasing the duration of SYS_Reset_XX in a
recent optimisation. Solution is more robust.

kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom