openwrt: Add OEM to OpenWrt UU6L script

Adds a script to automate process for installing OpenWrt for the
first time from an OEM UU6L device. See comments in script for
specifics.

BUG=b:330239428
TEST=successfully ran script to install openwrt on 2 different
OEM UU6Ls

Change-Id: I22e0dc7c11f8b33bfcc77673adf092497aaf06fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5379097
Tested-by: Jared Bennett <jaredbennett@google.com>
Commit-Queue: Jason Stanko <jstanko@google.com>
Auto-Submit: Jared Bennett <jaredbennett@google.com>
Reviewed-by: Jason Stanko <jstanko@google.com>
3 files changed