Add dependency on Soong config module definition file

Add a dependency on the Soong config module definition file in case
it wasn't called Android.bp.

Fixes: 148866376
Test: m checkbuild
Change-Id: Ib441881bcee52fd1dc3a8d1c5ae4f5f0b7efe3ce
diff --git a/android/soong_config_modules.go b/android/soong_config_modules.go
index f54e774..198108d 100644
--- a/android/soong_config_modules.go
+++ b/android/soong_config_modules.go
@@ -303,6 +303,7 @@
 	}
 
 	return ctx.Config().Once(key, func() interface{} {
+		ctx.AddNinjaFileDeps(from)
 		r, err := ctx.Config().fs.Open(from)
 		if err != nil {
 			ctx.PropertyErrorf("from", "failed to open %q: %s", from, err)