amd-pstate: Add support for core performance boost

Apply core performance boost in balanced + AC and performance and disable it when in power saver and balanced + battery.

This is based on https://lore.kernel.org/linux-pm/cover.1714112854.git.perry.yuan@amd.com/

There is still some pending discussion if the attribute should be global or per CPU. This PR will be adjusted based on the decision.