ACPI: CPPC: Rename EPP constants for clarity

ACPI: CPPC: Rename EPP constants for clarity

Update EPP (Energy Performance Preference) constants for more clarity:

 - Add CPPC_EPP_PERFORMANCE_PREF (0x00) for performance preference.

 - Rename CPPC_ENERGY_PERF_MAX to CPPC_EPP_ENERGY_EFFICIENCY_PREF (0xFF)
   for energy efficiency.

Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
[ rjw: Changelog edits ]
Link: https://patch.msgid.link/20260120145623.2959636-4-sumitg@nvidia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>