OMAPDSS: alloc dssdevs dynamically

We currently create omap_dss_devices statically in board files, and use
those devices directly in the omapdss driver. This model prevents us
from having the platform data (which the dssdevs in board files
practically are) as read-only, and it's also different than what we will
use with device tree.

This patch changes the model to be in line with DT model: we allocate
the dssdevs dynamically, and initialize them according to the data in
the board file's dssdev (basically we memcopy the dssdev fields).

The allocation and registration is done in the following steps in the
output drivers:

- Use dss_alloc_and_init_device to allocate and initialize the device.
  The function uses kalloc and device_initialize to accomplish this.
- Call dss_copy_device_pdata to copy the data from the board file's
  dssdev
- Use dss_add_device to register the device.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/dss.h

@@ -185,10 +185,13 @@ void dss_dsi_disable_pads(int dsi_id, unsigned lane_mask);
 int dss_set_min_bus_tput(struct device *dev, unsigned long tput);
 int dss_debugfs_create_file(const char *name, void (*write)(struct seq_file *));
 
-int omap_dss_register_device(struct omap_dss_device *dssdev,
-		struct device *parent);
-void omap_dss_unregister_device(struct omap_dss_device *dssdev);
-void omap_dss_unregister_child_devices(struct device *parent);
+struct omap_dss_device *dss_alloc_and_init_device(struct device *parent);
+int dss_add_device(struct omap_dss_device *dssdev);
+void dss_unregister_device(struct omap_dss_device *dssdev);
+void dss_unregister_child_devices(struct device *parent);
+void dss_put_device(struct omap_dss_device *dssdev);
+void dss_copy_device_pdata(struct omap_dss_device *dst,
+		const struct omap_dss_device *src);
 
 /* apply */
 void dss_apply_init(void);