common/image.c: move VxWorks header string out of CONFIG_CMD_ELF

Otherwise, when booting VxWorks kernel, the incorrect message will
be seen:

    ARM Unknown OS Kernel Image (uncompressed)

Signed-off-by: Miao Yan <miao.yan@windriver.com>

common/image.c

@@ -96,9 +96,9 @@ static const table_entry_t uimage_os[] = {
 	{	IH_OS_PLAN9,	"plan9",	"Plan 9",		},
 	{	IH_OS_RTEMS,	"rtems",	"RTEMS",		},
 	{	IH_OS_U_BOOT,	"u-boot",	"U-Boot",		},
+	{	IH_OS_VXWORKS,	"vxworks",	"VxWorks",		},
 #if defined(CONFIG_CMD_ELF) || defined(USE_HOSTCC)
 	{	IH_OS_QNX,	"qnx",		"QNX",			},
-	{	IH_OS_VXWORKS,	"vxworks",	"VxWorks",		},
 #endif
 #if defined(CONFIG_INTEGRITY) || defined(USE_HOSTCC)
 	{	IH_OS_INTEGRITY,"integrity",	"INTEGRITY",		},