regulator: act8865: fix build when OF is not enabled

act8846_matches and act8865_matches are defined only when OF is
enabled. Move references to them to the act8865_pdata_from_dt()
function to avoid a build error when OF is disabled.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>