rpm: needs mmu

Fixes:
http://autobuild.buildroot.net/results/7fa/7fa2bd8e464c6708095ec4038b6f3d534b10dd82/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
diff --git a/package/rpm/Config.in b/package/rpm/Config.in
index de06141..2492616 100644
--- a/package/rpm/Config.in
+++ b/package/rpm/Config.in
@@ -1,9 +1,11 @@
 comment "rpm needs a toolchain w/ threads"
 	depends on !BR2_TOOLCHAIN_HAS_THREADS
+	depends on BR2_USE_MMU # fork()
 
 config BR2_PACKAGE_RPM
 	bool "rpm"
 	depends on BR2_TOOLCHAIN_HAS_THREADS # beecrypt
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_BEECRYPT
 	select BR2_PACKAGE_POPT
 	select BR2_PACKAGE_OPENSSL