spi: s3c64xx: move controller information into driver data

Platform data is used to specify controller hardware specific information
such as the tx/rx fifo level mask and bit offset of rx fifo level. Such
information is not suitable to be supplied from device tree. Instead,
it can be moved into the driver data and removed from platform data.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Jaswinder Singh <jaswinder.singh@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>