sh: Initial support for SH-X3 prototype board.

This adds initial support for the SH-X3 prototype board.
Only simple logic for the IRQ controller and the heartbeat driver
for now.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/Makefile b/arch/sh/Makefile
index 97ac586..37cf636 100644
--- a/arch/sh/Makefile
+++ b/arch/sh/Makefile
@@ -118,6 +118,7 @@
 machdir-$(CONFIG_SH_EDOSK7705)			+= renesas/edosk7705
 machdir-$(CONFIG_SH_HIGHLANDER)			+= renesas/r7780rp
 machdir-$(CONFIG_SH_7710VOIPGW)			+= renesas/sh7710voipgw
+machdir-$(CONFIG_SH_X3PROTO)			+= renesas/x3proto
 machdir-$(CONFIG_SH_SH4202_MICRODEV)		+= superh/microdev
 machdir-$(CONFIG_SH_LANDISK)			+= landisk
 machdir-$(CONFIG_SH_TITAN)			+= titan