spi: dw: move piece of code out of condition

There is no sense to keep a member assignment in the internal structure inside
the condition which reprograms HW. It makes code readability better if kept
outside of the condition.

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