libopenvswitch.pc: Add missing libs for a static build.

SSL, BPF, lcap-ng and other libraries are in use by a static library,
so they has to be linked while building applications with that static
library, i.e. 'pkg-config --libs --static libopenvswitch' must return
-lssl, -lcap-ng, etc. in the output for a successful build.

For dynamic library (non-private Libs) all these libraries will be
dynamically linked to libopenvswitch.so, so the application will
pick them up without having a direct dependency.

Acked-by: Frode Nordahl <frode.nordahl@canonical.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

lib/libopenvswitch.pc.in

@@ -7,5 +7,5 @@ Name: libopenvswitch
 Description: Open vSwitch library
 Version: @VERSION@
 Libs: -L${libdir} -lopenvswitch
-Libs.private: @LIBS@
+Libs.private: @LIBS@ @SSL_LIBS@ @CAPNG_LDADD@ @LIBBPF_LDADD@
 Cflags: -I${includedir}