Calls to PWM drivers connected through I2C can sleep.
Use the new can_sleep property.
Acked-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NFlorian Vaussard <florian.vaussard@epfl.ch>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

The driver supports the following PWM outputs:
TWL4030 PWM0 and PWM1
TWL6030 PWM1 and PWM2

On TWL4030 the PWM signals are muxed. Upon requesting the PWM the driver
will select the correct mux so the PWM can be used. When the PWM has been
freed the original configuration is going to be restored.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>