Merge remote-tracking branches 'regulator/topic/doc',...

Merge remote-tracking branches 'regulator/topic/doc', 'regulator/topic/enable', 'regulator/topic/fan53555', 'regulator/topic/fixed', 'regulator/topic/gpio', 'regulator/topic/lp3971', 'regulator/topic/lp872x' and 'regulator/topic/max14577' into regulator-next