It appears the st7920 requires a longer delay when switching from
command to data mode (and vice-versa). Slower MCUs don't show a
problem because the klipper command processing time results in a
sufficient delay. However, some of the faster MCUs can process
klipper commands fast enough that the next st7920 transfer is sent too
fast. Add an additional delay to account for this.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Kevin O'Connor