powercap: intel_rapl: Add a symbol namespace for intel_rapl exports

powercap: intel_rapl: Add a symbol namespace for intel_rapl exports

Cleanup of the intel_rapl common driver requires introducing additional
exported helper and lifecycle functions. Before adding new exports,
create a dedicated symbol namespace for intel_rapl and update the
relevant interface drivers to explicitly import it.

This makes the intended usage of these symbols explicit, avoids
polluting the global namespace, and prepares the codebase for the
ongoing RAPL refactoring.

No functional changes are intended.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://patch.msgid.link/20260212233044.329790-2-sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>