spi: mpc512x-psc: Remove redundant code to get bus_num from DT

For DT case, spi core will call of_alias_get_id() and set master->bus_num if it
was not set.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
1 file changed