regulator: palmas: Use of_property_read_bool to read "ti,warm-reset" DT property

It does not make sense to assign return value of of_property_read_u32() to
pdata->reg_init[idx]->warm_reset. Use of_property_read_bool() to read
"ti,warm-reset" DT property instead which will return correct setting
for pdata->reg_init[idx]->warm_reset.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>