Adopt kernel-rpm-macros from redhat-rpm-config

No changes are being made to the individual files added here; they're 1:1 copies of the ones in redhat-rpm-config.

Note the kernel-rpm-macros version - the latest c9s build is versioned after its parent SRPM which is redhat-rpm-config-184-1, so we need to make this one NVR-newer to allow for clean upgrades.

The respective removals from redhat-rpm-config are tracked in #1959924.

Resolves: #1959914