leds: add output driver configuration for pca9633 led driver

the pca9633 leds driver can be used in open-drain or totem pole (a.k.a.
push/pull) output driver mode; default is the later

the patch allows to set the output driver mode using platform data (similar to
configuration inferface provided by the tca6507 led driver)

v2: move leds-pca9633.h to include/linux/platform_data/ (Bryan Wu)

Signed-off-by: Peter Meerwald <p.meerwald@bct-electronic.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>