um: Fix W=1 missing-include-dirs warnings

Currently when using "W=1" with UML builds, there are over 700 warnings
like so:

  CC      arch/um/drivers/stderr_console.o
cc1: warning: ./arch/um/include/uapi: No such file or directory [-Wmissing-include-dirs]

but arch/um/ does not have include/uapi/ at all, so add that
subdir and put one Kbuild file into it (since git does not track
empty subdirs).

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: linux-um@lists.infradead.org
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/arch/um/include/uapi/asm/Kbuild b/arch/um/include/uapi/asm/Kbuild
new file mode 100644 (file)
index 0000000..f66554c
--- /dev/null
+++ b/arch/um/include/uapi/asm/Kbuild
@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0