test: call timer subsystem finalize at exit

test: call timer subsystem finalize at exit

The eal_flags_autotest checks that no hugepage map files are left behind
after a process exits, which can only be the case if all allocations made
from DPDK heaps were freed back to the freelist, resulting in the
hugepage map files being unlinked automatically.  Add a call to
rte_timer_subsystem_finalize() at application exit time to release
allocations now made by the timer library.

Fixes: c0749f7096c7 ("timer: allow management in shared memory")

Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>