pwm: lpss: Include headers we are the direct user of

For the sake of integrity, include headers we are the direct
user of.

Replace the inclusion of device.h by a forward declaration
of struct device plus a (cheaper) of types.h as device.h is
an expensive include (measured in compiler effort).

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>