Patch merged into coreboot/master: lib/compute_ip_checksum: mark data buffer as const

the following patch was just integrated into master:
commit 30c64be4ce1c3082c0dc0399ce0a5418698ad0cc
Author: Aaron Durbin 
Date:   Sat Dec 3 21:05:53 2016 -0600

lib/compute_ip_checksum: mark data buffer as const

compute_ip_checksum() doesn't manipulate the data it is passed.
    Therefore, mark it as const.

BUG=chrome-os-partner:56151

Change-Id: I54cff9695a886bacd6314aa441d96aaa7a991101
    Signed-off-by: Aaron Durbin 
    Reviewed-on: https://review.coreboot.org/17714
    Tested-by: build bot (Jenkins)
    Reviewed-by: Duncan Laurie 
    Reviewed-by: Furquan Shaikh 
    Reviewed-by: Paul Menzel

See https://review.coreboot.org/17714 for details.

-gerrit