add .set_sar_specs to allow configuring SAR power limitations on the
frequency ranges from the userland.
Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: YN Chen <YN.Chen@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>