package/util-linux: libuuid needs -lintl

When gettext is needed (with locales), libuuid needs to be linked
against -lintl.

In dynamic link, this is solved via the DT_NEEDED ELF tag, but for
static links, it does not get pulled in automatically.

Fix that by adding a Libs.private section to uuid.pc, but only if
it needed.

First part at fixing:
    http://autobuild.buildroot.net/results/c46/c467aeec258909bb82eda77123803944f97d8df8/



Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>