tinyhttpd: needs mmu

Fixes:
http://autobuild.buildroot.net/results/2a3b5ab3ef58443c1bf86df5498df2f145cd840c/

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

package/tinyhttpd/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_TINYHTTPD
 	bool "tinyhttpd"
+	depends on BR2_USE_MMU # fork()
 	help
 	  A relatively simple webserver written as a school project. It is
 	  exceedingly simple, threaded and handles basic CGI scripts.