spi: rockchip: remove master pointer from dev data

In almost all cases we already have a pointer to the
spi master structure where we have the driver data.

The only exceptions are the dma callbacks which are
easily fixed by passing them the master and using
spi_master_get_devdata to retrieve the driver data.

Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mark Brown <broonie@kernel.org>