regulator: fixed: Prevent NULL pointer dereference when !CONFIG_OF

Use of_device_get_match_data which has NULL test for match before
dereference match->data. Add NULL test for drvtype so it still works
for fixed_voltage_ops when !CONFIG_OF.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Philippe Schenker <philippe.schenker@toradex.com>
Link: https://lore.kernel.org/r/20190922022928.28355-1-axel.lin@ingics.com


Signed-off-by: Mark Brown <broonie@kernel.org>