iwlwifi: refactor the SAR tables from mvm to acpi

Refactored the SAR related functions from iwlmvm to acpi
in order to make it shared between different opmodes
in addition to removing unused variable ppag_rev.

Signed-off-by: Ihab Zhaika <ihab.zhaika@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>