Persimmon: disable APU PCIe port 3

According to DB-FT1 rev. D schematics the APU PCIe lane 3 is unconnected.
Reflect this fact in the mainboard code.

Change-Id: Ic98f4a63ef971628df7fbf97f56b80ebe7cb8517
Signed-off-by: Jens Rottmann <JRottmann@LiPPERTembedded.de>
Reviewed-on: http://review.coreboot.org/2447
Tested-by: build bot (Jenkins)
Reviewed-by: Peter Stuge <peter@stuge.se>
1 file changed