czmq: needs MMU

Fixes:
http://autobuild.buildroot.net/results/6dd/6dd6954e5ab8c422070e53b0e616e1b1a821c626/



Also, remove the Blackfin toolchain dependencies as these are redundant now
since Blackfin is a noMMU arch.

[Peter: propagate to filemq as well]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>