如何配置php libmysqlclient.so查找目录

I've just created Buildroot system with PHP and MySQL. After doing php -v i saw:

Cannot open libmysqlclient.so.16 (...)

I checked under

/usr/lib/

There was no libmysqlclient.so.16, but it was under:

/usr/lib/mysql/

I created a symlink in:

/usr/lib/

And everything started to work.

But now I looked into my host system and there is no symlink, however PHP works.

Where can I set parameter to ./configure saying where to look for libmysqlclient?