sqlcipher: disable tcl support

In commit b1dcb1c2 a fix was attempted at fixing a build failure where
sqlcipher finds the distribution tcl and tries to build against it.
sqlcipher has two tcl usage scenarios: host-tcl which is required to
actually build it, and target tcl to build bindings.
Since cross-compilation of the bindings isn't clean it fails as well,
and since it wasn't a feature before either just disable it completely,
since the wrong fix makes the sqlcipher build failures worse.
Fixes:
http://autobuild.buildroot.net/results/fc0/fc0528de7fed2f34f503fe8dd8b4c21ded0d6dff/



Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>