target/linux/config: allow enabling TCP syncookie support

Signed-off-by: Phil Sutter <phil@nwl.cc>

target/linux/config/Config.in.network

@@ -5,7 +5,7 @@ config ADK_KERNEL_IP_FIB_HASH
 	default y
 
 config ADK_KERNEL_SYN_COOKIES
-	boolean
+	boolean "IP: TCP syncookie support"
 	default n
 
 config ADK_KERNEL_IP_PNP_BOOTP