pwm: add period and polarity to struct pwm_lookup

Add period and polarity members to struct pwm_lookup so that platforms
using the lookup table can be treated the same way as those using the
device tree.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --cc drivers/pwm/core.c
Simple merge

diff --cc include/linux/pwm.h
Simple merge