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.org


Signed-off-by: Mark Brown <broonie@kernel.org>