spi: ppc4xx: Use SPI_MODE_X_MASK

Use SPI_MODE_X_MASK instead of open coded variant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510131217.49357-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed