MAINTAINERS.yml: Add libmctp module maintainership

Adds myself, nashif, and inteljiangwe1 to the maintainers file covering
the libmctp module.

Signed-off-by: Tom Burdick <thomas.burdick@intel.com>

MAINTAINERS.yml

@@ -4786,6 +4786,18 @@ West:
   labels:
     - "platform: Intel"
 
+"West project: libmctp":
+  status: maintained
+  maintainers:
+    - teburd
+  collaborators:
+    - nashif
+    - inteljiangwe1
+  files:
+    - samples/modules/mctp/
+  labels:
+    - "area: MCTP"
+
 "West project: libmetal":
   status: odd fixes
   collaborators: