Patch merged into coreboot/master: abuild: allow specifying multiple targets by mainboard descriptor

the following patch was just integrated into master:
commit f6dc5443185ea07fd305426a67a1b0aa57003d96
Author: Patrick Georgi 
Date:   Sat Oct 31 09:13:26 2015 +0100

abuild: allow specifying multiple targets by mainboard descriptor

abuild -t EMULATION_QEMU_UCB_RISCV,EMULATION_SPIKE_UCB_RISCV works now

Change-Id: I49d8cd86e21ede724d8daa441b728efa1f6ea1fa
    Signed-off-by: Patrick Georgi 
    Reviewed-on: http://review.coreboot.org/12281
    Tested-by: build bot (Jenkins)
    Reviewed-by: Martin Roth

See http://review.coreboot.org/12281 for details.

-gerrit