[coreboot-gerrit] Patch merged into coreboot/master: mb/lenovo/t400: Implement hybrid graphic in romstage

the following patch was just integrated into master:
commit f9d5308690e96002dbeab77b78e499dcd2d3a42f
Author: Arthur Heymans 
Date:   Mon Jan 2 16:16:45 2017 +0100

mb/lenovo/t400: Implement hybrid graphic in romstage

The hybrid driver select by DRIVERS_LENOVO_HYBRID_GRAPHICS doesn't work
    for t400/t500.
    Replace it with a custom romstage implementation.

Tested on Lenovo T500 with dual graphics:
    * Intel Native GFX init
    * AMD VBios
    * GNU Linux 4.8.13
    * SeaBios as payload
    * Discrete is working (44 W)
    * Integrated is working (24 W)
    * Switchable is working (34 W)
    ** Both GPUs are enabled, with Intel being connected to the panel
    ** DRI_PRIME allows to use AMD GPU
    ** ACPI doesn't seem to work (no vgaswitcheroo)

Depends on Change-Id: I4dc00005270240c048272b2e4f52ae46ba1c9422
    Depends on Change-Id: If389016f3bb0c4c2fd0b826914997a87a9137201

Change-Id: I7496876e9b434d4a2388e1ede27ac604670339b7
    Signed-off-by: Arthur Heymans 
    Signed-off-by: Patrick Rudolph 
    Reviewed-on: https://review.coreboot.org/18010
    Tested-by: build bot (Jenkins)
    Reviewed-by: Alexander Couzens

See https://review.coreboot.org/18010 for details.

-gerrit