platform/x86/intel-uncore-freq: Add attributes to show agent types

platform/x86/intel-uncore-freq: Add attributes to show agent types

Currently, users need detailed hardware information to understand the
scope of controls within each uncore domain. Uncore frequency controls
manage subsystems such as core, cache, memory, and I/O. The UFS TPMI
provides this information, which can be used to present the scope more
clearly.

Each uncore domain consists of one or more agent types, with each agent
type controlling one or more uncore hardware subsystems. For example, a
single agent might control both the core and cache.

Introduce a new attribute called "agent_types." This attribute displays
a list of agents, separated by space character.

The string representations for agent types are as follows:
	For core agent: core
	For cache agent: cache
	For memory agent: memory
	For I/O agent: io

These agent types are read during probe time for each cluster and stored
as part of the struct uncore_data.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20250508230250.1186619-2-srinivas.pandruvada@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>