Move of_register_spi_devices() call from drivers to
spi_register_master(). Also change the function to use
the struct device_node pointer from master spi device
instead of passing it as function argument.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

This patch adds support for populating an SPI bus based on data in the
OF device tree.  This is useful for powerpc platforms which use the
device tree instead of discrete code for describing platform layout.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>