regulator: palmas: Remove a redundant setting for warm_reset

Current code read "ti,warm_reset" of property twice, and set
pdata->reg_init[idx]->warm_reset twice. Read and set it once is enough.

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