thermal: streamline get_trend callbacks

thermal: streamline get_trend callbacks

The .get_trend callback in struct thermal_zone_device_ops has the prototype:
        int (*get_trend) (struct thermal_zone_device *, int,
                          enum thermal_trend *);
whereas the .get_trend callback in struct thermal_zone_of_device_ops has:

        int (*get_trend)(void *, long *);

Streamline both prototypes and add the trip argument to the OF callback
aswell and use enum thermal_trend * instead of an integer pointer.

While the OF prototype may be the better one, this should be decided at
framework level and not on OF level.

Change-Id: I39c5a38a22c7a2177a35338bc63c8ba36983a7b0
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>