ARM: OMAP: Allow I2C bus driver to be compiled as a module

Fixes a linker error when OMAP I2C bus driver is compiled as a module:

   ERROR: "i2c_register_board_info" [arch/arm/plat-omap/i2c.ko] undefined!

The I2C utility functions used for board initialization should be always
built-in.

Signed-off-by: Aaro Koskinen <Aaro.Koskinen@nokia.com>
Acked-by: Jarkko Nikula  <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/plat-omap/include/mach/common.h b/arch/arm/plat-omap/include/mach/common.h
index ef70e2b..e746ec7 100644
--- a/arch/arm/plat-omap/include/mach/common.h
+++ b/arch/arm/plat-omap/include/mach/common.h
@@ -35,7 +35,7 @@
 extern struct sys_timer omap_timer;
 extern void omap_serial_init(void);
 extern void omap_serial_enable_clocks(int enable);
-#ifdef CONFIG_I2C_OMAP
+#if defined(CONFIG_I2C_OMAP) || defined(CONFIG_I2C_OMAP_MODULE)
 extern int omap_register_i2c_bus(int bus_id, u32 clkrate,
 				 struct i2c_board_info const *info,
 				 unsigned len);