Add Makefile for the midi host example

Author: atoktoto

examples/host/midi_rx/Makefile

@@ -0,0 +1,9 @@
+include ../../../tools/top.mk
+include ../../make.mk
+INC += \
+	src \
+	$(TOP)/hw \
+# Example source
+EXAMPLE_SOURCE += $(wildcard src/*.c)
+SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
+include ../../rules.mk