regulator: core: Let boot-on regulators be powered off

Boot-on regulators are always kept on because their use_count value
is now incremented at boot time and never cleaned.

Only increment count value for alway-on regulators.
regulator_late_cleanup() is now able to power off boot-on regulators
when unused.

Fixes: 05f224ca66 ("regulator: core: Clean enabling always-on regulators + their supplies")
Signed-off-by: Pascal Paillet <p.paillet@st.com>
Link: https://lore.kernel.org/r/20191113102737.27831-1-p.paillet@st.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/core.c

@@ -1403,7 +1403,9 @@ static int set_machine_constraints(struct regulator_dev *rdev,
 			rdev_err(rdev, "failed to enable\n");
 			return ret;
 		}
-		rdev->use_count++;
+
+		if (rdev->constraints->always_on)
+			rdev->use_count++;
 	}
 
 	print_constraints(rdev);