SPI: PRIMA2: use the newest APIs of PINCTRL to fix compiling errors

Fix the compiling errors:
drivers/spi/spi-sirf.c: In function 'spi_sirfsoc_probe':
drivers/spi/spi-sirf.c:563: error: implicit declaration of function 'pinmux_get'
drivers/spi/spi-sirf.c:563: warning: assignment makes pointer from integer without a cast
drivers/spi/spi-sirf.c:568: error: implicit declaration of function 'pinmux_enable'
drivers/spi/spi-sirf.c:602: error: implicit declaration of function 'pinmux_disable'
drivers/spi/spi-sirf.c:603: error: implicit declaration of function 'pinmux_put'
make[3]: *** [drivers/spi/spi-sirf.o] Error 1

Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>