regulator: 88pm8607: Fix off-by-one value range checking in the case of no id is matched

In the case of no id is matched, the variable i is equal to
ARRAY_SIZE(pm8607_regulator_info).

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>