cpufreq: Move CPPC configs to common Kconfig and add RISC-V

CPPC related config options are currently defined only in ARM specific
file. However, they are required for RISC-V as well. Instead of creating
a new Kconfig.riscv file and duplicating them, move them to the common
Kconfig file and enable RISC-V too.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20240208034414.22579-3-sunilvl@ventanamicro.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>