Implement SBI CPPC extension. This extension is only available when
OpenSBI platform provides a CPPC device to generic library.
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Sunil V L