scarthgap: license issue in build time

[jiaxshi]

Describe the bug
Some recipes can not be built due to "do_create_spdx: Cannot find any text for license BSD"

There are multi-varaint of BSD license. Such as:

./BSD-2-Clause
./BSD-3-Clause
./BSD-4-Clause
./BSD-1-Clause
./BSD-3-Clause-Open-MPI

"BSD" is used for short in package.xml of some ROS projects. Then "LICENSE = "BSD" is used in generated recipes by superflore. And there 's not BSD license file which causes "Cannot find any text for license BSD" failure.

Known recipes:
sensor-msgs-py
image-transport
image-transport-plugins
cv-bridge

Temporary solution
We can add bbappends to reset LICENSE one by one... or
cp BSD-3-Clause BSD