[redhat] Enable Simple Frame Buffer support

Enable the sysfb simple frame buffer.

• v3:

  • simplify properly, and enable this in general, not just for aarch64

• v2:

  • fix typo (CONFIG_SYSFB_SIMPLEFB, not CONFIG_SYSFB_SIMPLE)
  • simplify fedora and common config usage, enabling for aarch64 only

Signed-off-by: Al Stone ahs3@redhat.com