make `go` optional

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/common/cmd_boot.c b/common/cmd_boot.c
index 7b603d3..0afd939 100644
--- a/common/cmd_boot.c
+++ b/common/cmd_boot.c
@@ -28,6 +28,8 @@
 #include <command.h>
 #include <net.h>
 
+#ifdef CONFIG_CMD_GO
+
 /* Allow ports to override the default behavior */
 __attribute__((weak))
 unsigned long do_go_exec (ulong (*entry)(int, char * const []), int argc, char * const argv[])
@@ -67,6 +69,8 @@
 	"      passing 'arg' as arguments"
 );
 
+#endif
+
 U_BOOT_CMD(
 	reset, 1, 0,	do_reset,
 	"Perform RESET of the CPU",