Travis fix - only allow ultralcd_st7920_u8glib_rrd_AVR.cpp to compile when ST7920 selected

Travis is having problems at:  https://github.com/MarlinFirmware/Marlin/pull/8560   

So...   doing a direct commit to get things correct.   Bugfix_v1.1.x does not have this bug.  Nothing needs to be done to that branch.

These changes may need to be warmed over.  I tried to fix things with
the least amount of disruption.   I just wanted to get the bugfix_v2.0.0
branch working for people again.

Previous fix did not work as expected when axeis not homed. It raise Z but never return to original position

Followup to 13a3fb1acc

Can LCD shift registers keep up with faster MCUs?

Remove assert and unused code since it is implemented in pinsDebug_plus_70.h

This will solve 2 issues on tool change.
1) when no home is done ("no_move" is set) tool change should never move X & Y because... I don't know where I am...only Z should be adjusted to avoid bed collision if other nozzle is lower than current.
Since no move no bed level matrix should be applied
2) When SWITCHING_NOZZLE is enabled and system is homed there are two movements to go to destination, but first can move Z to older position and then crash on the bed

Add and bugfix pins