coreutils_6.9: Update the older coreutils to no longer provide 'su'

coreutils_6.9: Update the older coreutils to no longer provide 'su'

'su' was removed from newer versions of coreutils, and in OE-Core
we pick up 'su' from shadow instead. So simply remove the binary
from the install image to match expected behavior and avoid failures
due to conflicting 'su' binaries during do_rootfs when building
non-GPLv3 images.

(From OE-Core rev: b4c5fc7c025ff864280be9678e6dd856971c71d7)

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>