This commit adds a debugfs interface that can be used to list the
current internal state of the PWM devices registered with the PWM
framework.
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>