sh: add support for SMSC Polaris platform

Polaris is an SMSC reference platform with a SH7709S CPU and LAN9118
ethernet controller.  This patch adds support for it.

Updated following feedback from Nobuhiro Iwamatsu.

Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Reviewed-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/boards/Kconfig b/arch/sh/boards/Kconfig
index 48c043b..dcc1af8 100644
--- a/arch/sh/boards/Kconfig
+++ b/arch/sh/boards/Kconfig
@@ -261,6 +261,13 @@
 	depends on CPU_SUBTYPE_SH5_101 || CPU_SUBTYPE_SH5_103
 	select SYS_SUPPORTS_PCI
 
+config SH_POLARIS
+	bool "SMSC Polaris"
+	select CPU_HAS_IPR_IRQ
+	depends on CPU_SUBTYPE_SH7709
+	help
+	  Select if configuring for an SMSC Polaris development board
+
 endmenu
 
 source "arch/sh/boards/mach-r2d/Kconfig"