MFC r268771, r268796 by nwhitehorn:

MFC r268771, r268796 by nwhitehorn:

r268771:
  Allow console drivers active from early boot to be used with
  xf86-video-scfb, rather than only drivers attached later on. This
  involves a small amount of code duplication with dev/fb/fbd.c, which
  will fixed later on.

  Also improve performance of vt_blank() by making it not read from the
  framebuffer unnecessarily.

r268796:
  Fix embarassing typos I made.

Sponsored by:	The FreeBSD Foundation

git-svn-id: svn://svn.freebsd.org/base/stable/10@270980 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f