[ARM] 5419/1: ep93xx: fix build warnings about struct i2c_board_info

Fix build warnings due to struct i2c_board_info in <mach/platform.h>

Patch "5311/1: add core support for built in i2c bus" is causing 11 of
39 the build warnings with Kautobuild for ep93xx_defconfig on kernel
2.6.29-rc5-git4.  This patch fixes it.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-ep93xx/include/mach/platform.h

@@ -4,6 +4,8 @@
 
 #ifndef __ASSEMBLY__
 
+struct i2c_board_info;
+
 struct ep93xx_eth_data
 {
 	unsigned char	dev_addr[6];