arm/km: fix i2c mux define for km_kirkwood_128m16 target

Due to the i2c mux rework in u-boot we now have only to specify the
busnumber and not the whole mux configuration.
Signed-off-by: NHolger Brunck <holger.brunck@keymile.com>
Acked-by: NHeiko Schocher <hs@denx.de>

include/configs/km_kirkwood.h

@@ -43,7 +43,7 @@
 #define CONFIG_SYS_KWD_CONFIG \
 		$(SRCTREE)/$(CONFIG_BOARDDIR)/kwbimage_128M16_1.cfg
 #define CONFIG_KM_DISABLE_PCIE
-#define KM_IVM_BUS			"pca9544a:70:9"	/* I2C2 (Mux-Port 1)*/
+#define CONFIG_KM_IVM_BUS		1	/* I2C2 (Mux-Port 1)*/
 
 /* KM_NUSA */
 #elif defined(CONFIG_KM_NUSA)