spi: dw-pci: correct number of chip selects

The commit d58cf5ff brought a second controller to the list of supported
devices and changed a number of the chip selects. Besides the previous number
was wrong anyway the mentioned patch makes it wrong again meanwhile has a
proper numbers in the commit message. Indeed, SPI1 has 5 bits and SPI2 has 2
bits, but it does not mean to have power of two of this bits as a possible
number of the chip selects. So, this patch fixes it eventually.

Fixes: d58cf5ff (spi: dw-pci: describe Intel MID controllers better)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org