uboot-kirkwood: fix default bootcmd for Seagate Dockstar

Fix the default value for the 'bootcmd' environment variable.
Therefore make the default bootcmd work for buildbot's images.

Signed-off-by: Paul Wassi <p.wassi@gmx.at>

package/boot/uboot-kirkwood/patches/110-dockstar.patch

@@ -28,7 +28,7 @@
 -	"bootm 0x800000 0x1100000"
 +	"ubi part ubi; " \
 +	"ubi read 0x800000 kernel; " \
-+	"bootz 0x800000"
++	"bootm 0x800000"
  
 -#define CONFIG_MTDPARTS		"mtdparts=orion_nand:1m(uboot),-(root)\0"
 +#define CONFIG_MTDPARTS \