Add support to build the AMD uncore driver as a module.

This is in order to facilitate development without having
to reboot the kernel in most cases.
Signed-off-by: NKim Phillips <kim.phillips@amd.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210817221048.88063-8-kim.phillips@amd.com