regulator: core: Fix off-on-delay-us for always-on/boot-on regulators

Regulators marked with "regulator-always-on" or "regulator-boot-on"
as well as an "off-on-delay-us", may run into cycling issues that are
hard to detect.

This is caused by the "last_off" state not being initialized in this
case.

Fix the "last_off" initialization by setting it to the current kernel
time upon initialization, regardless of always_on/boot_on state.

Signed-off-by: Christian Kohlschütter <christian@kohlschutter.com>
Link: https://lore.kernel.org/r/FAFD5B39-E9C4-47C7-ACF1-2A04CD59758D@kohlschutter.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/core.c

@@ -1565,6 +1565,9 @@ static int set_machine_constraints(struct regulator_dev *rdev)
 			rdev->constraints->always_on = true;
 	}
 
+	if (rdev->desc->off_on_delay)
+		rdev->last_off = ktime_get();
+
 	/* If the constraints say the regulator should be on at this point
 	 * and we have control then make sure it is enabled.
 	 */
@@ -1592,8 +1595,6 @@ static int set_machine_constraints(struct regulator_dev *rdev)
 
 		if (rdev->constraints->always_on)
 			rdev->use_count++;
-	} else if (rdev->desc->off_on_delay) {
-		rdev->last_off = ktime_get();
 	}
 
 	print_constraints(rdev);