regulator: machine.h: fix kernel-doc "bad line"

Fix warning caused by a blank/empty line:

../include/linux/regulator/machine.h:115: warning: bad line:
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210628015422.8845-1-rdunlap@infradead.orgSigned-off-by: Mark Brown <broonie@kernel.org>

include/linux/regulator/machine.h

@@ -112,7 +112,7 @@ struct notification_limit {
  * @over_voltage_limits:	Limits for acting on over voltage.
  * @under_voltage_limits:	Limits for acting on under voltage.
  * @temp_limits:		Limits for acting on over temperature.
-
+ *
  * @max_spread: Max possible spread between coupled regulators
  * @max_uV_step: Max possible step change in voltage
  * @valid_modes_mask: Mask of modes which may be configured by consumers.