sh: intc: initial irqdomain support.

Trivial support for irq domains, using either a linear map or radix tree
depending on the vector layout.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/sh/intc/Kconfig b/drivers/sh/intc/Kconfig
index c88cbcc..a305731 100644
--- a/drivers/sh/intc/Kconfig
+++ b/drivers/sh/intc/Kconfig
@@ -1,3 +1,7 @@
+config SH_INTC
+	def_bool y
+	select IRQ_DOMAIN
+
 comment "Interrupt controller options"
 
 config INTC_USERIMASK