lib/oe/sbom30: Prefix aliases with "http://spdx.org/spdxdocs/"

lib/oe/sbom30: Prefix aliases with "http://spdx.org/spdxdocs/"

While the SPDX ID aliases are primarily intended for internal use by the
SPDX code, they are used in places where a valid SPDX ID is expected. In
order to make sure that they still conform to this, prefix them with
"http://spdx.org/spdxdocs/openembedded-alias"

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>