[Intel-gfx] Updated fastboot bits

[Jesse Barnes]

Still need to mash these into the pipe_config bits, but with the PCH PLL
readout, at least they don't crash after DPMS anymore.  So that patch
may be ok to apply as-is; I think the main bits needing rework involve
the mode readout checks in intel_fb.c.  They belong in intel_display.c
as part of the state readout into an adjusted_mode struct.

Jesse