[OE-core] Staging machine specific kernel headers in sysroot

[Andre McCurdy]

Say I have a kernel driver with a user space API (simple struct and
ioctl definitions) defined in a header file which is part of my
machine specific kernel. The header file is not found in the upstream
kernel, so doesn't clash with anything in linux-libc-headers.

Is it OK to use something like the following in my kernel recipe?

  sysroot_stage_all_append () {
    install -d ${SYSROOT_DESTDIR}/${includedir}/linux
    install -m644 ${S}/include/linux/foo.h
${SYSROOT_DESTDIR}/${includedir}/linux/
  }

I've tested it and everything seems to work fine, but I'm wondering if
bypassing do_install like that is going to cause problems somehow?