Revert "leds: remove omap-pwm driver"

This reverts commit b8dfd97c54914b1b95d182c744a9bc6bef44c001.

Change-Id: I0b68ffc369b212ff166ee93f4a8a210cd102663d
Revert "panel-backlight: change from omap-pwm led driver to o2micro backlight driver"

This reverts commit addde5b255a48b5904b48cac53c27dd0409bcc29.

Change-Id: Ib9ac8c025cde1e1ba20b8d2c6fc24aa6db7d678c