Add zephyr module support

Add external support for nanopb to zephyr as a module

Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>
diff --git a/zephyr/module.yml b/zephyr/module.yml
new file mode 100644
index 0000000..207809a
--- /dev/null
+++ b/zephyr/module.yml
@@ -0,0 +1,4 @@
+name: nanopb
+build:
+  cmake-ext: True
+  kconfig-ext: True