skylake: Rework microcode include path

Remove the microcode include path config options and include
the mainboard blob directory by default.

BUG=chrome-os-partner:42109
BRANCH=none
TEST=emerge-glados coreboot
CQ-DEPEND=CL:*221987, CL:*222225, CL:*222195, CL:285922

Change-Id: Ie959c7e8413afbfdafdbc87c80b6fbebaee5fea1
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: ce988b08ef1d81b08994d689f3fe273d2fc2f448
Original-Change-Id: I12d0d60df0d8c366d4478ceae88eba9fb058e4b8
Original-Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/285150
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Tested-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/11053
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
4 files changed