linux-phytec-ti

spi: dw-mid: change magic numbers to the constants

Instead of using magic numbers in the code we create a bit map definition of
the DMACR register and use it.

There is no functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>