The PWM unit on MT7981 uses different register offsets than previous
MediaTek PWM units. Add support for these new offsets and add support
for PWM on MT7981 which has 3 PWM channels, one of them is typically
used for a temperature controlled fan.
While at it, also reorder pwm_mediatek_of_data entries to restore
alphabetic order.
Signed-off-by: Daniel Golle <daniel@makrotopia.org> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>