spi: pxa2xx: Drop useless comment in the pxa2xx_ssp.h

No need to have file name inside file.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200826151455.55970-3-andriy.shevchenko@linux.intel.com


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