irqchip: Add Kconfig menu

Add a menu for IRQ chip drivers. This makes the Device drivers menu be more
consistent (listing "subsystems" instead of specific options) and makes the
IRQCHIP options be listed in expected places for 'make menu|xconfig'.

Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Jason Cooper <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

drivers/irqchip/Kconfig

@@ -1,3 +1,5 @@
+menu "IRQ chip support"
+
 config IRQCHIP
 	def_bool y
 	depends on OF_IRQ
@@ -321,3 +323,5 @@ config IRQ_UNIPHIER_AIDET
 	select IRQ_DOMAIN_HIERARCHY
 	help
 	  Support for the UniPhier AIDET (ARM Interrupt Detector).
+
+endmenu