pdo_mysql.so

[Dick Hoogendijk]

I need pdo_mysql.so for Drupal7 to work correctly, but I only see pdo.so 
and pdo_sqlite.so in the php5 extension directory. So, I checked the 
'make config' to see if I forgot something. But the option to build 
pdo_mysql is not there. How do I get this pdo_mysql.so file?