chromeos-ec: EC_FIRMWARE_UNIBUILD{,_FAKE} -> get_each_model_conf_value_set

This is one of many ebuilds that will have this variable (or similar)
replaced with a call to this function.

BUG=chromium:741043,b:64117873

TEST=emerge chromeos-ec ec-utils coreboot for both pyro and reef-uni;
confirm output equivalent to before change

CQ-DEPEND=CL:619869

Change-Id: Ieef2912ff03e2728c3edd3aa72e85d746400a72e
Reviewed-on: https://chromium-review.googlesource.com/614310
Commit-Ready: Jason Clinton <jclinton@chromium.org>
Tested-by: Jason Clinton <jclinton@chromium.org>
Reviewed-by: Jason Clinton <jclinton@chromium.org>
6 files changed