perf/arm-cmn: Improve format attr printing

Take full advantage of our formats being stored in bitfield form, and
make the printing even more robust and simple by letting printk do all
the hard work of formatting bitlists.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/50459f2d48fc62310a566863dbf8a7c14361d363.1725474584.git.robin.murphy@arm.com


Signed-off-by: Will Deacon <will@kernel.org>