ARM: shmobile: henninger: specify EXTAL frequency

When creating the initial device tree for the Henninger board, I've overlooked that EXTAL frequency needs to be overridden there. The 'sh-sci' driver managed to work somehow but the SDHI driver that I've tried to enable just hanged with the default EXTAL frequency of 0...

---
This patch is against 'renesas-devel-v3.15-rc3-20140429' tag of Simon Horman's 'renesas.git' repo.

 arch/arm/boot/dts/r8a7791-henninger.dts |    4 ++++
 1 file changed, 4 insertions(+)

Index: renesas/arch/arm/boot/dts/r8a7791-henninger.dts
===================================================================
@@ -35,6 +35,10 @@
 	};
 };
 
+&extal_clk {
+	clock-frequency = <20000000>;
+};
+
 &pfc {
 	scif0_pins: serial0 {
 		renesas,groups = "scif0_data_d";

Thanks, I have queued this up.