Add Deuteron ProbNN definition

Add Deuteron ProbNN definition

Cherry picked from 2018-patches, see merge request !1230 (merged)

@jonrob FYI

• [2018-04-12 10:39] Validation started with lhcb-gaudi-head#1831
• [2018-04-12 16:40] Validation started with lhcb-gaudi-merge#480
• [2018-04-12 17:24] Validation started with lhcb-gaudi-merge#481
• [2018-04-13 00:11] Validation started with lhcb-tdr-test#118
• [2018-04-13 00:11] Validation started with lhcb-clang-test#919
• [2018-04-13 00:12] Validation started with lhcb-head#1817
• [2018-04-13 00:13] Validation started with lhcb-gaudi-head-py3#122
• [2018-04-13 00:14] Validation started with lhcb-gaudi-head#1832

merged

mentioned in commit d83c5868