build: always build package/kernel/linux
If no in-tree module packages are selected, the build system does not process
package/kernel/linux. This package is required for building the virtual
'kernel' package, which is specified as a dependency for all kernel packages.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
The usage of granular `SOURCE_DATE_EPOCH` for packages is an
incrementing integer which could be useful for downstream tooling,
therefore add it to the packages manifest.
Signed-off-by: Paul Spooren <mail@aparcar.org>
