spi: qup: Fix build error due to a typo

Fix below build error when CONFIG_PM_RUNTIME=y:

C [M]  drivers/spi/spi-qup.o
drivers/spi/spi-qup.c: In function 'spi_qup_pm_suspend_runtime':
drivers/spi/spi-qup.c:712:12: error: 'QUP_CLOCK_AUTO_GATE' undeclared (first use in this function)
drivers/spi/spi-qup.c:712:12: note: each undeclared identifier is reported only once for each function it appears in
drivers/spi/spi-qup.c: In function 'spi_qup_pm_resume_runtime':
drivers/spi/spi-qup.c:725:13: error: 'QUP_CLOCK_AUTO_GATE' undeclared (first use in this function)
make[2]: *** [drivers/spi/spi-qup.o] Error 1
make[1]: *** [drivers/spi] Error 2
make: *** [drivers] Error 2

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>