Patch merged into coreboot/master: symbols: add '_' to pci_drivers and cpu_drivers symbols

the following patch was just integrated into master:
commit 037581542b8e4571437ea34fb0244ad2ef43b6a3
Author: Aaron Durbin 
Date:   Thu Sep 3 17:23:08 2015 -0500

symbols: add '_' to pci_drivers and cpu_drivers symbols

In order to prepare for more unification of the linker
    scripts prefix pci_drivers, epci_drivers, cpu_drivers, and
    ecpu_drivers with an underscore.

BUG=chrome-os-partner:44827
    BRANCH=None
    TEST=Built different boards includes ones w/ and w/o relocatable
         ramstage.

Change-Id: I8918b38db3b754332e8d8506b424f3c6b3e06af8
    Signed-off-by: Aaron Durbin 
    Reviewed-on: http://review.coreboot.org/11506
    Tested-by: build bot (Jenkins)
    Reviewed-by: Stefan Reinauer

See http://review.coreboot.org/11506 for details.

-gerrit