mkdir /cfg from within a package context

We're slowly getting rid of the overlays.

Change-Id: Ibf5f464d81a5e9f9d7cd4e56fd4dd0a661ccb05f
diff --git a/board/czechlight/common/overlay/cfg/.keep b/board/czechlight/common/overlay/cfg/.keep
deleted file mode 100644
index e69de29..0000000
--- a/board/czechlight/common/overlay/cfg/.keep
+++ /dev/null
diff --git a/package/czechlight-cfg-fs/czechlight-cfg-fs.mk b/package/czechlight-cfg-fs/czechlight-cfg-fs.mk
index a0c2e8c..a7c2e25 100644
--- a/package/czechlight-cfg-fs/czechlight-cfg-fs.mk
+++ b/package/czechlight-cfg-fs/czechlight-cfg-fs.mk
@@ -16,6 +16,7 @@
 	$(INSTALL) -D -m 0644 \
 		$(BR2_EXTERNAL_CZECHLIGHT_PATH)/package/czechlight-cfg-fs/etc-fstab \
 		$(TARGET_DIR)/etc/fstab
+	mkdir -p $(TARGET_DIR)/cfg
 	mkdir -p $(TARGET_DIR)/usr/lib/systemd/system/local-fs.target.wants/
 	$(INSTALL) -D -m 0644 \
 		$(BR2_EXTERNAL_CZECHLIGHT_PATH)/package/czechlight-cfg-fs/etc-overlay.service \