regulator: max77686: Fix checkpatch warnings

Fix below checkpatch warnings:

$ scripts/checkpatch.pl -f drivers/regulator/max77686.c
ERROR: return is not a function, parentheses are not required
+       return (DIV_ROUND_UP(rdev->desc->uV_step

WARNING: line over 80 characters
+       .ops            = &max77686_buck_dvs_ops,                               \

total: 1 errors, 1 warnings, 339 lines checked

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>