spi: pxa2xx-pci: Remove unused code

pcim_iomap_table() can't fail when called after pcim_iomap_regions(). Moreover,
we already dereference returned value and kernel will crash if it is not
correct.

Remove obvious leftover of commit 0202775b ("spi/pxa2xx-pci: switch to use
pcim_* interfaces").

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