spi: pxa2xx: Revert "Only claim CS GPIOs when the slave device is created"

There is a valid case to call setup() following by setup_cs() several
times for the same chip.

With the commit

  676a4e3b ("spi: pxa2xx: Only claim CS GPIOs when the slave device is created")

it is not possible anymore due to GPIO line being requested already
during the first call to setup_cs().

For now, revert the commit to make things work again.

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