Patch merged into coreboot/master: src/lib: Update Makefile to keep build/spd.bin rule private

the following patch was just integrated into master:
commit 8e4bb3164a1af2a988c63dfa92777de9d60fae3f
Author: Martin Roth 
Date:   Sun Jan 29 18:11:36 2017 -0700

src/lib: Update Makefile to keep build/spd.bin rule private

The rule to make spd.bin that's in src/lib is for the 'generic_spd_bin'
    implementation.  It wasn't guarded though, so it was generating a build
    warning for any other platform that generated an spd.bin file.

Sample warning that this fixes:
    src/mainboard/gizmosphere/gizmo/Makefile.inc:42:
    warning: overriding recipe for target 'build/spd.bin'
    src/lib/Makefile.inc:298: warning: ignoring old recipe for target
    'build/spd.bin'

Change-Id: Iadd6743f8ae476969bf36f99b918f04c04172d1d
    Signed-off-by: Martin Roth 
    Reviewed-on: https://review.coreboot.org/18261
    Tested-by: build bot (Jenkins)
    Reviewed-by: Paul Menzel 
    Reviewed-by: Patrick Georgi

See https://review.coreboot.org/18261 for details.

-gerrit