package/tpm-tools: fix build with locale support

tpm-tools needs to link with libintl when locale support is enabled.

However, tpm-tools' build-system internally builds a couple of static libraries
used to build the final programs.
When linking these libraries or the final programs, we need to explicitly tell
the linker to link with libintl in order to resolve all the missing symbols.

Fixes:
  http://autobuild.buildroot.org/results/560/56020558ec298ac4007bf7f6ce030b3f2fa1157d/
  http://autobuild.buildroot.org/results/17f/17fc6ca79765fd9ecdacec4f5a2b58caa554d48d/
  http://autobuild.buildroot.org/results/2d2/2d2c655429df62da2b8746a564fc064609e96001/
  http://autobuild.buildroot.org/results/d52/d5259b83e7a269bca019d024366aa201f5a174fd/
  http://autobuild.buildroot.org/results/11c/11cb0d1e51459e75e5f376cb07ce0188f8f050c4/
  http://autobuild.buildroot.org/results/bad/bad9a97b4fff00732f2efb043bbb76a99963c491/
  http://autobuild.buildroot.org/results/2f8/2f8bd534e6fcd9d356fe9087cb1394b9b2c4192c/


  and many others...

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Cc: Noé Rubinstein <nrubinstein@aldebaran.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>