regulator: lochnagar: Use a consisent comment style for SPDX header

Update the rest of the comment at the start of the file to also use C++
style comments to match the required style of the SPDX header.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed