omap: i2c: Fix muxing for command line enabled bus

The commit b63128e81214cc2db2995d690438055c26d213a5 broke the pin muxing
for I2C busses that are enabled from the kernel command line.

Fix this by defining the board registration function omap_register_i2c_bus
in common platform code as it was before but keep the muxing in architecture
dependent files.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/i2c.c b/arch/arm/mach-omap2/i2c.c
index 789ca8c..7951ae1 100644
--- a/arch/arm/mach-omap2/i2c.c
+++ b/arch/arm/mach-omap2/i2c.c
@@ -25,9 +25,7 @@
 
 #include "mux.h"
 
-int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
-			  struct i2c_board_info const *info,
-			  unsigned len)
+void __init omap2_i2c_mux_pins(int bus_id)
 {
 	if (cpu_is_omap24xx()) {
 		const int omap24xx_pins[][2] = {
@@ -51,6 +49,4 @@
 		sprintf(mux_name, "i2c%i_sda.i2c%i_sda", bus_id, bus_id);
 		omap_mux_init_signal(mux_name, OMAP_PIN_INPUT);
 	}
-
-	return omap_plat_register_i2c_bus(bus_id, clkrate, info, len);
 }