libpcre: Drop old/stale patch

According to my tests this incorrect symbols resolution at runtime no
longer happens. Ubuntu is still carrying the patch but also probably
doesn't need to, they are also on a much older version. It sounds
like there was once a linkage bug somewhere which has likely been
resolved since.

Drop the patch as it doesn't seem needed anymore. If it were a real
issue it should be submitted upstream too, the status is incorrect.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>