of: Check for NULL pointer in of_find_property ...

The console layer calls of_device_is_stdout_path for a new console. When
we are booting without devicetree then of_chosen is NULL which makes barebox
crash. Check for a NULL pointer in of_find_property to prevent this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of gpio: Build gpio helper only when gpiolib is selected ...

Otherwise the functions needed by the helper won't be available.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

switch all platform_bus device/driver registering to platform_driver/device_register ...

now register_driver and register_device are for bus only usage.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

of: Add devicetree partition parsing ...

Helper code to probe mtd partitions from the devicetree.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of: add devicetree probing support ...

This adds code to probe devices from a devicetree. Most helper
functions are directly imported from Linux.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>