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.

MK2_MULTIPLEXER does not require E2/E3 stepper pins

[2.0.x] Followup for MESH_EDIT_GFX_OVERLAY

[2.0.x] Implement NANODLP_Z_SYNC for 2.0.x

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.

[2.0.x]  Adapt G26 to work for all meshes

[2.0.x] Tool change bad behaviour fix

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

[2.0.x] Add BIQU BQ111-A4 board

[2.0.x] Fix up LCD init / charset

[2.0.x] Add support for Ultratronics Pro v1.0 and fix compiling for Due HAL

[2.0.x] LP1768 - fix PWMs

Followup to 13a3fb1acc

[2.0.x] General code clean/comment

Can LCD shift registers keep up with faster MCUs?

Remove pin count check for MIGHTYBOARD_REVE