Avoid crash on EGL initialization failure with multi-GPU
When plugging in a DisplayLink dock, gnome-shell crashed in Mutter.
This series makes EGL initialization failure not fatal alone. A KMS device that fails EGL can still be used with the CPU copy mode as a secondary GPU.
This series does not fix the actual crash when a
MetaGpuKms lacks the associated GPU data structure, it merely avoids it by trying harder to make the data structure available nevertheless.
This series allows me to hotplug and unplug a DisplayLink dock successfully on Ubuntu 19.04.
Fixes: #542 (closed)