arm64, topology: enable use of init_cpu_capacity_cppc()

Now that the arch topology driver provides a method of setting CPU
capacity values based on information on highest performance from CPPC,
use this functionality on arm64 platforms.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>