Patch merged into coreboot/master: Microcode: Show a useful warning when microcode bins are missing

the following patch was just integrated into master:
commit 85653748a4a503fc8fae82a12e5b7d162f50348c
Author: Martin Roth 
Date:   Thu Dec 22 10:29:20 2016 -0700

Microcode: Show a useful warning when microcode bins are missing

Because the binary repo is disabled by default, we get frequent
    questions about why the build failed, relating to microcode in the
    binary repository.

- Show an error saying that the file is missing instead of the typical
    make error of no rule to build the file.
    - Show a note encouraging users to try enabling the binary repo if it's
    not enabled.

Change-Id: If4148c18cfb781ed2932bd2ae4a289b621afdebf
    Signed-off-by: Martin Roth 
    Reviewed-on: https://review.coreboot.org/17940
    Tested-by: build bot (Jenkins)
    Reviewed-by: Paul Menzel 
    Reviewed-by: Nico Huber

See https://review.coreboot.org/17940 for details.

-gerrit