control: Add basic MCTP Control Protocol handler

This will respond to the 4 mandatory MCTP Control Protocol commands.
Applications can register supported types using mctp_control_add_type().

Change-Id: Ia904bcbe118626adf9254ffa71dd8e17fbdfc9b7
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
diff --git a/Makefile.am b/Makefile.am
index 984a5d4..bd7db2b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3,7 +3,7 @@
 lib_LTLIBRARIES = libmctp.la
 libmctp_la_SOURCES = core.c alloc.c log.c \
 		     libmctp-alloc.h libmctp-log.h \
-		     libmctp-cmds.h
+		     libmctp-cmds.h control.c
 include_HEADERS = libmctp.h
 
 if LIBMCTP_BINDING_serial