regulator: 88pm800: Get rid of struct pm800_regulators

The struct pm800_regulators only has 2 members: *chip and *map.
The pm800_data->chip is not used. The pm800_data->map is not necessary.
Thus remove the struct pm800_regulators.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>