Patch merged into coreboot/master: mtrr: Define a function for obtaining free var mtrr

the following patch was just integrated into master:
commit 331ac1b07896140a14dbb079b3cb907762cec218
Author: Furquan Shaikh 
Date:   Wed Mar 16 16:12:06 2016 -0700

mtrr: Define a function for obtaining free var mtrr

Instead of hard-coding var mtrr numbers in code, use this function to
    identify the first available variable mtrr. If no such mtrr is
    available, the function will return -1.

Change-Id: I2a1e02cdb45c0ab7e30609641977471eaa2431fd
    Signed-off-by: Furquan Shaikh 
    Reviewed-on: https://review.coreboot.org/14115
    Tested-by: build bot (Jenkins)
    Reviewed-by: Andrey Petrov

See https://review.coreboot.org/14115 for details.

-gerrit