Enable fbdev for vmwgfx kernel driver [Testing: issue1280]

This is supposed to fix the display issue on
VMware ESXi 5.5, vSphere 5.0 and 5.5 etc where
boot hangs after "Waiting for /dev/" but it's
actually just the display that's hanging.

See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=714929
for further information.

Thanks: Andreas Gredler <jimmy@grml.org>