Fix x86_64 build: wrong macro
Directory "brp-tizen.d" is located in /usr/lib/rpm but was set to
%{_libdir}/rpm which expands to /usr/lib64/rpm for 64 bit architectures.
Using the macro %{_rpmconfigdir} solves this issue since it allways
expands to /usr/lib/rpm.
The issue was introduced by commit:
ca1b55134e1f144f7d06d69e9edb8197a3cfc9e1
Change-Id: Ida24145c24913f782d1756130525c42ba71645e5
Signed-off-by: Kévin THIERRY <kevin.thierry@open.eurogiciel.org>