perf/x86/rapl: Support multiple RAPL unit quirks

There will be more platforms with different fixed energy units.
Enhance the code to support different RAPL unit quirks for different
platforms.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Link: https://lore.kernel.org/r/20200811153149.12242-3-rui.zhang@intel.com