cpmodem: add missing dependencies

Change-Id: Ieed637bd424a601c37edc52ef1e47acff8d2e8c0
diff --git a/cpmodem_shim/Kbuild b/cpmodem_shim/Kbuild
index 880321d..8a2e07a 100644
--- a/cpmodem_shim/Kbuild
+++ b/cpmodem_shim/Kbuild
@@ -1,2 +1,3 @@
 obj-m	+= cpmodem_shim.o
+cpmodem_shim-y := cpmodem_shim_main.o cpmodem_wrapper.o
 ccflags-y += $(EXTRA_CFLAGS)