spi: dw-pci: remove free for resources allocated with devm_*

It's not necessary to free resources allocated with devm_*
and free them may lead to double free.

Fixes: 04f421e7

 ('spi: dw: use managed resources')
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@linaro.org>