Patch merged into coreboot/master: lib/regscript: Add exclusive-or (xor) support

the following patch was just integrated into master:
commit 6bcbe5749b9f1a82004299bb63fba7e99b8ed358
Author: Lee Leahy 
Date:   Sat Apr 23 07:58:27 2016 -0700

lib/regscript: Add exclusive-or (xor) support

Add xor support which enables toggling of a bit:
    * REG_SCRIPT_COMMAND_RXW enum value
    * REG_*_RXW* macros to support using REG_SCRIPT_COMMAND_RXW
    * REG_*_XOR* macros to support using REG_SCRIPT_COMMAND_RXW
    * reg_script_rxw routine to perform and/xor operation
    * case in reg_script_run_step to call reg_script_rxw

TEST=Build and run on Galileo Gen2

Change-Id: I50a492c7c2643df5dc2d2fa7113e3722c1e480c7
    Signed-off-by: Lee Leahy 
    Reviewed-on: https://review.coreboot.org/14495
    Tested-by: build bot (Jenkins)
    Reviewed-by: Aaron Durbin

See https://review.coreboot.org/14495 for details.

-gerrit