PDO drivers are released via PECL; all the usual rules for PECL extensions apply. Packaging is accomplished by creating a valid package.xml file and then running:
$ pecl package
This will create a tarball named PDO_SKEL-X.Y.Z.tgz.
Before releasing the package, you should test that it builds correctly; if you've made a mistake in your config.m4 or package.xml files, the package may not function correctly. You can test the build, without installing anything, using the following invocation:
$ pecl build package.xml
Once this is proven to work, you can test installation:
$ pecl package $ sudo pecl install PDO_SKEL-X.Y.X.tgz
Full details about package.xml can be found in the PEAR Programmer's documentation (https://pear.php.net/manual/).