packet/bmp: Missing Constants for BMP RFC7854
packet/bmp: Missing Constants for BMP RFC7854

Signed-off-by: IWASE Yusuke <bb80e84cc9f5a8f01385872ee89032beb5d4eba7@gmail.com>

ishidawataru/gobgp,a16/gobgp,Dipsingh/gobgp,a16/gobgp,fujita/gobgp,a16/gobgp,ishidawataru/gobgp,osrg/gobgp,fujita/gobgp,osrg/gobgp,fujita/gobgp,Dipsingh/gobgp,a16/gobgp,Dipsingh/gobgp,fujita/gobgp,j-kato/gobgp,tamihiro/gobgp,a16/gobgp,osrg/gobgp,osrg/gobgp,ishidawataru/gobgp,j-kato/gobgp,a16/gobgp,j-kato/gobgp,tamihiro/gobgp,a16/gobgp,tamihiro/gobgp,tamihiro/gobgp