The legacy mysql_connect also has a parameter 'client_flag' that can be used to set the mysql parameter.
The client_flags parameter can be a combination of the following
  constants: 128 (enable LOAD DATA LOCAL handling), MYSQL_CLIENT_SSL,
  MYSQL_CLIENT_COMPRESS, MYSQL_CLIENT_IGNORE_SPACE or
  MYSQL_CLIENT_INTERACTIVE. Read the section about MySQL client
  constants for further information. In SQL safe mode, this parameter is
  ignored.
  http://php.net/function.mysql-connect
Example:
$db = mysql_connect($host, $user, $pass, FALSE, 128);
However, you may also encounter the following error:
ERROR 29 (HY000): File '/var/www/.../mysql_import.csv' not found (Errcode: 13)
In which case, you may need to check your App Armor settings to allow MySQL access to the import files on the filesystem.
In particular I added:
  /import/ r,
  /import/* rw,
To give MySQL read/write access to /import
e.g: Sample App Armor profile
cat /etc/apparmor.d/usr.sbin.mysqld 
# vim:syntax=apparmor
# Last Modified: Tue Jun 19 17:37:30 2007
#include <tunables/global>
/usr/sbin/mysqld {
  #include <abstractions/base>
  #include <abstractions/nameservice>
  #include <abstractions/user-tmp>
  #include <abstractions/mysql>
  #include <abstractions/winbind>
  capability dac_override,
  capability sys_resource,
  capability setgid,
  capability setuid,
  network tcp,
  /etc/hosts.allow r,
  /etc/hosts.deny r,
  /etc/mysql/*.pem r,
  /etc/mysql/conf.d/ r,
  /etc/mysql/conf.d/* r,
  /etc/mysql/*.cnf r,
  /usr/lib/mysql/plugin/ r,
  /usr/lib/mysql/plugin/*.so* mr,
  /usr/sbin/mysqld mr,
  /usr/share/mysql/** r,
  /var/log/mysql.log rw,
  /var/log/mysql.err rw,
  /var/lib/mysql/ r,
  /var/lib/mysql/** rwk,
  /var/log/mysql/ r,
  /var/log/mysql/* rw,
  /var/run/mysqld/mysqld.pid w,
  /var/run/mysqld/mysqld.sock w,
  /run/mysqld/mysqld.pid w,
  /run/mysqld/mysqld.sock w,
  # Custom import folders start
  # These folders will also be read/writeable by mysql.
  /import/ r,
  /import/* rw,
  # Custom import folders end
  /sys/devices/system/cpu/ r,
  # Site-specific additions and overrides. See local/README for details.
  #include <local/usr.sbin.mysqld>
}
After that MySQL could read files from the /import directory.