[ARM] Kirkwood: Hook up I2C

Hook up I2C on Marvell Kirkwood.  Tested on a QNAP TS-219 which has
RTC connected through I2C.

Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
diff --git a/arch/arm/mach-kirkwood/common.h b/arch/arm/mach-kirkwood/common.h
index 9e52826..c66a250 100644
--- a/arch/arm/mach-kirkwood/common.h
+++ b/arch/arm/mach-kirkwood/common.h
@@ -37,6 +37,7 @@
 void kirkwood_sata_init(struct mv_sata_platform_data *sata_data);
 void kirkwood_sdio_init(struct mvsdio_platform_data *mvsdio_data);
 void kirkwood_spi_init(void);
+void kirkwood_i2c_init(void);
 void kirkwood_uart0_init(void);
 void kirkwood_uart1_init(void);