ARM: STi: Ensure requested STi's SysCfg Controlled IRQs are enabled at boot

This driver is used to enable System Configuration Register controlled
External, CTI (Core Sight), PMU (Performance Management), and PL310 L2
Cache IRQs prior to use.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>

arch/arm/mach-sti/Kconfig

 menuconfig ARCH_STI
 	bool "STMicroelectronics Consumer Electronics SOCs" if ARCH_MULTI_V7
 	select ARM_GIC
+	select ST_IRQCHIP
 	select ARM_GLOBAL_TIMER
 	select PINCTRL
 	select PINCTRL_ST