UBUNTU: d-i: Add bnxt_en_bpo to nic-modules.

BugLink: http://bugs.launchpad.net/bugs/1734757Suggested-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Acked-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Kleber Souza <kleber.souza@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

debian.master/d-i/modules/nic-modules

@@ -41,6 +41,7 @@ bmac ?
 bnx2 ?
 bnx2x ?
 bnxt_en ?
+bnxt_en_bpo ?
 bonding ?
 brcmfmac ?
 brcmsmac ?