spi: mpc512x-psc: Fix compile errors

spi: mpc512x-psc: Fix compile errors

My patch created compilation bugs in the MPC512x-PSC driver.
Fix them up.

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: linuxppc-dev@lists.ozlabs.org
Reported-by: kernel test robot <lkp@intel.com>
Fixes: a30e7d1f7c37 (" spi: mpc512x-psc: Convert to use GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220201234535.569973-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>