dhcp: needs MMU

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/dhcp/Config.in

@@ -1,5 +1,7 @@
 config BR2_PACKAGE_DHCP
 	bool "isc dhcp"
+	# fork()
+	depends on BR2_USE_MMU
 	help
 	  DHCP relay agent from the ISC DHCP distribution.