aiccu: patched Makefile to enable static linking

Fixes autobuild errors:
http://autobuild.buildroot.net/results/308087e1f85e822dec8b73a3ed892c7cd2376cbd/
http://autobuild.buildroot.net/results/9fb298d4e09a6f9b88207909d583dce05392048e/



[Peter: use pkg-config instead of hardcoding libraries for gnutls]
Signed-off-by: Michael Rommel <rommel@layer-7.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>