lib/sku: remove legacy /opt/oem/etc/BRAND_CODE reading

This applied to Monroe only, which is now AUE.

BUG=chromium:1114735
TEST=compiles

Change-Id: Ief898c745ec6b819a0d28805974daddb9620bfd4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/mosys/+/2441699
Tested-by: Jack Rosenthal <jrosenth@chromium.org>
Auto-Submit: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
1 file changed