--- zzzz-none-000/linux-4.4.60/include/uapi/Kbuild	2017-04-08 07:53:53.000000000 +0000
+++ scorpion-7490-727/linux-4.4.60/include/uapi/Kbuild	2021-02-04 17:41:59.000000000 +0000
@@ -13,3 +13,13 @@
 header-y += xen/
 header-y += scsi/
 header-y += misc/
+
+avm_labile_headers += drivers/
+
+# Check existence of avm_labile_headers ('wildcard' functions requires complete
+# path, 'header-y' forbids absolute path names).
+header-y += $(patsubst $(srctree)/include/uapi/%,%,\
+  $(wildcard \
+   $(addprefix $(srctree)/include/uapi/,\
+    $(avm_labile_headers))))
+