buildroot

php: security bump to version 7.0.12

See http://www.php.net/ChangeLog-7.php#7.0.12 since there are no CVEs
out yet.

And drop upstream patch.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>