drivers: spi_nrfx_spim: Fix handling of extended SPIM configuration
drivers: spi_nrfx_spim: Fix handling of extended SPIM configuration

Fill the `rx_delay` field in the SPIM configuration structure only when
the RXDELAY feature is present in a given SPIM instance, to prevent
compilation errors when some other SPIM instance is enabled together
with SPIM3.

Signed-off-by: Andrzej Głąbek <6788b8d556a8a447102338fc996c42180ecff44e@nordicsemi.no>

galak/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,Vudentz/zephyr,finikorg/zephyr