spi: pxa2xx: Use pxa_ssp_enable()/pxa_ssp_disable() in the driver

There are few places that repeat the logic of pxa_ssp_enable() and
pxa_ssp_disable(). Use them instead of open coded variants.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510124134.24638-10-andriy.shevchenko@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>