regulator: Allow boot_on regulators to be disabled by clients

Rather than incrementing the reference count for boot_on regulators
(which prevents them being disabled later on) simply force the
regulator to be enabled when applying the constraints. Previously
boot_on was essentially equivalent to always_on.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index 1eb861c..5de7aa3 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -73,7 +73,9 @@
  *
  * @always_on: Set if the regulator should never be disabled.
  * @boot_on: Set if the regulator is enabled when the system is initially
- *           started.
+ *           started.  If the regulator is not enabled by the hardware or
+ *           bootloader then it will be enabled when the constraints are
+ *           applied.
  * @apply_uV: Apply the voltage constraint when initialising.
  *
  * @input_uV: Input voltage for regulator when supplied by another regulator.