ARM: mvebu: specify I2C bus frequency on Armada 370 DB

In commit 249f3822 ('ARM: mvebu: add
audio support to Armada 370 DB'), the I2C bus 0 was enabled on the
Armada 370 DB board, and an I2C codec was described as being connected
on this bus.

However, this commit forgot to define the I2C bus frequency, which
leads the i2c-mv64xxx to fail probing, as it cannot calculate the baud
rate multiplier/divisor to derive the I2C bus frequency from the core
SoC frequency. It makes audio completely unusable, as the I2C bus is
not probed, and therefore the audio codec is not probed either.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397806908-7550-2-git-send-email-thomas.petazzoni@free-electrons.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/armada-370-db.dts

@@ -67,6 +67,7 @@
 			i2c@11000 {
 				pinctrl-0 = <&i2c0_pins>;
 				pinctrl-names = "default";
+				clock-frequency = <100000>;
 				status = "okay";
 				audio_codec: audio-codec@4a {
 					compatible = "cirrus,cs42l51";