Fix klibc Debian specific build trouble

Simply remove the headers_install invocation and rely on linux-libc-dev.

With these changes:

(the extra chmod was needed to allow for umask > 022) I could compile,
link and run this program:

#include <unistd.h>

int main(void)
{
write(1, "Hello world\n", 12);
return 0;
}

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[ added multi arch support ]
Signed-off-by: Colin Watson <cjwatson@ubuntu.com>
Signed-off-by: maximilian attems <max@stro.at>
[ fixed cross building ]
Signed-off-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
Gbp-Pq: Name klibc-linux-libc-dev

klibc (2.0.4-9+rpi1) stretch-staging; urgency=medium

  [changes brought forward from 2.0.4-2+rpi1 by Peter Michael Green <plugwash@p10link.net> at Wed, 26 Nov 2014 22:01:00 +0000]
  * Change compiler settings to values suitable for raspberry pi

[dgit import unpatched klibc 2.0.4-9+rpi1]

Import klibc_2.0.4-9+rpi1.debian.tar.xz

[dgit import tarball klibc 2.0.4-9+rpi1 klibc_2.0.4-9+rpi1.debian.tar.xz]

Import klibc_2.0.4.orig.tar.gz

[dgit import orig klibc_2.0.4.orig.tar.gz]