FP4: Initial proprietary-files.txt

Fingerprint: Fairphone/FP4eea/FP4:11/RKQ1.210503.001/FP3N:user/release-keys
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 4c8d837..f282412 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -63,3 +63,9 @@
 TARGET_RECOVERY_UI_MARGIN_WIDTH := 10
 TARGET_USERIMAGES_USE_EXT4 := true
 TARGET_USERIMAGES_USE_F2FS := true
+
+# Security patch level
+VENDOR_SECURITY_PATCH := 2021-11-05
+
+# Inherit the proprietary files
+include vendor/fairphone/FP4/BoardConfigVendor.mk