We need to set ownership of the license files after copying into the rootfs.
We also need to ensure we don't overwrite the rootfs files outside rootfs
generation, hence only write there when the new rootfs function parameter
is True.
[YOCTO #12961]
(From OE-Core rev: 6aa0eeaa4d31a440700f7695174de2a1dcc54866)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>