Commit 4ccae37db1aa77a1d15098c3720ea6e2d383fbdc introduced a sed command
line to modify a file that only exists in 4.8.0, thus do_configure of
4.7.4 was failing; so make this conditional upon the file existing.
(From OE-Core rev: 0b948d20b835387702a4f5e103eaae5b4a330edd)
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>