bindings: AST LPC binding implementation

Add a binding implementation for the ASPEED 2500 LPC + KCS devices.
While not a standard, this does give us a hardware binding
implementation to use on current hardware.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/Makefile.inc b/Makefile.inc
index 98df834..fd63032 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -1,6 +1,6 @@
 LIBMCTP_DIR ?= libmctp/
 LIBMCTP_OBJS = core.o alloc.o
-LIBMCTP_BINDINGS ?= serial
+LIBMCTP_BINDINGS ?= serial astlpc
 
 LIBMCTP_OBJS += $(LIBMCTP_BINDINGS:%=%.o)