cryptsetup: Add libintl for UCLIBC toolchain

Fixes autobuild error
http://autobuild.buildroot.net/results/cc1a65b9554bc2ece1b3ea8b51cd805b9bda7e86/



Adding libintl to the libraries list for cryptsetup when using a
uclibc toolchain and locale support is enabled.

Signed-off-by: Clayton Shotwell <clshotwe@rockwellcollins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>