configurations: mtjefferson: Add Backplane card

This adds Backplane card to mtjefferson_bp.json

Tested: Latest CI build passed

Signed-off-by: Hieu Huynh <hieuh@os.amperecomputing.com>
Change-Id: Ifff34c9b15343600cdf8d5ba9523afece9239f4d
diff --git a/meson.build b/meson.build
index 0b90c4d..3801f02 100644
--- a/meson.build
+++ b/meson.build
@@ -159,6 +159,7 @@
     'mori_motherboard.json',
     'mtjade.json',
     'mtjefferson_bmc.json',
+    'mtjefferson_bp.json',
     'mtjefferson_mb.json',
     'mtmitchell_bmc.json',
     'mtmitchell_bp.json',