MFC r268772 by nwhitehorn:

MFC r268772 by nwhitehorn:

  Allow efifb to be used with xf86-video-scfb. This is important for EFI
  systems without either a CSM or real graphics drivers, such as my
  Lenovo Haswell laptop.

  This provides working X with the small complication of a console
  cursor permanently overlaid on the upper-left corner of the screen
  that will be dealt with later.

  Also remove some redundant screen clearing.

Sponsored by:	The FreeBSD Foundation