tbs2910: explicitly set boot address

Set missing boot address in bootm command. This fixes the error:
 Wrong Image Format for bootm command
 ERROR: can't get kernel image!

Reported-by: Uwe Scheffler <scheffler.u@web.de>
Signed-off-by: Soeren Moch <smoch@web.de>
Tested-by: Uwe Scheffler <scheffler.u@web.de>

include/configs/tbs2910.h

@@ -190,7 +190,7 @@
 	"bootargs_upd=setenv bootargs console=ttymxc0,115200 " \
 			"rdinit=/sbin/init enable_wait_mode=off\0" \
 	"bootcmd_mmc=run bootargs_mmc; mmc dev 2; " \
-			"mmc read 0x10800000 0x800 0x4000; bootm\0" \
+			"mmc read 0x10800000 0x800 0x4000; bootm 0x10800000\0" \
 	"bootcmd_up1=load mmc 1 0x10800000 uImage\0" \
 	"bootcmd_up2=load mmc 1 0x10d00000 uramdisk.img; " \
 			"run bootargs_upd; " \