powercap / RAPL: add IDs for future Xeon CPUs

Enable RAPL driver on Xeon cpu id 0x56.

Signed-off-by: Jacob Pan <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/powercap/intel_rapl.c

···
 	RAPL_CPU(0x45, rapl_defaults_core),/* Haswell ULT */
 	RAPL_CPU(0x4C, rapl_defaults_atom),/* Braswell */
 	RAPL_CPU(0x4A, rapl_defaults_atom),/* Tangier */
+	RAPL_CPU(0x56, rapl_defaults_core),/* Future Xeon */
 	RAPL_CPU(0x5A, rapl_defaults_atom),/* Annidale */
 	{}
 };