dt/spi: Eliminate users of of_platform_{,un}register_driver

Get rid of users of of_platform_driver in drivers/spi.  The
of_platform_{,un}register_driver functions are going away, so the
users need to be converted to using the platform_bus_type directly.

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

diff --cc drivers/spi/mpc512x_psc_spi.c
Simple merge

diff --cc drivers/spi/mpc52xx_psc_spi.c
Simple merge

diff --cc drivers/spi/mpc52xx_spi.c
Simple merge

diff --cc drivers/spi/spi_fsl_espi.c
Simple merge

diff --cc drivers/spi/spi_fsl_lib.c
Simple merge

diff --cc drivers/spi/spi_fsl_lib.h
Simple merge

diff --cc drivers/spi/spi_fsl_spi.c
Simple merge

diff --cc drivers/spi/spi_ppc4xx.c
Simple merge