of13: set default ethernet types for MPLS actions

0x8847 (MPLS) for PUSH_MPLS
0x0800 (IP) for POP_MPLS

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
of12: set default ethernet types for MPLS actions

0x8847 (MPLS) for PUSH_MPLS
0x0800 (IP) for POP_MPLS

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>