tftpd: depends on MMU

This package needs MMU. Hence added dependency on BR2_USE_MMU

Fixes:
http://autobuild.buildroot.net/results/3e1/3e16d8c9ae3b77393e082c3dd9b7b3de9aa040c0//

Signed-off-by: Yuvaraj Patil <yuvaraj.patil@wipro.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tftpd/Config.in

@@ -1,4 +1,5 @@
 config BR2_PACKAGE_TFTPD
 	bool "tftpd"
+	depends on BR2_USE_MMU # fork()
 	help
 	  HPA's Trivial File Transfer Protocol (tftp) server.