create-spdx/sbom: Ensure files don't overlap between machines

create-spdx/sbom: Ensure files don't overlap between machines

Currently the by-id and by-namespace SPDX files are created without reference
to PACKAGE_ARCH. This means that for two machines using a common package architecture
(e.g. genericx86-64 and qqemux86-64), there would be overlapping files. This means
that the build of one can remove files from the other leading to build failures. An
example would be:

MACHINE=qemux86-64 bitbake core-image-minimal
MACHINE=genericx86-64 bitbake core-image-minimal
MACHINE=qemux86-64 bitbake linux-yocto -c clean
MACHINE=genericx86-64 bitbake core-image-minimal -C rootfs

To fix this, add PACKAGE_ARCH to the path used for the files and use a search
path based upon PACKAGE_ARCHS to access them.

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