security/vboot: Add function to read UDC enable flag

This change adds a helper function to read USB Device Controller (UDC)
enable flag from VBNV.

BUG=b:78577893
BRANCH=poppy

Change-Id: Ifd1e9b0781ffee242d695b72287632bc944a50c7
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/25846
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
3 files changed