irqchip/stm32: Select GENERIC_IRQ_CHIP

This patch adds GENERIC_IRQ_CHIP to stm32 exti
config.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/Kconfig

@@ -306,6 +306,7 @@ config EZNPS_GIC
 config STM32_EXTI
 	bool
 	select IRQ_DOMAIN
+	select GENERIC_IRQ_CHIP
 
 config QCOM_IRQ_COMBINER
 	bool "QCOM IRQ combiner support"