Back in SDK 5.07 when we shipped that particular version we were still hosting the Linux kernel at arago-project.org:
http://arago-project.org/git/projects/linux-am33x.git
My suggestion would be:
- git clone git://arago-project.org/git/projects/linux-am33x.git
- cd linux-am33x.git
- git checkout v3.2_AM335xPSP_04.06.00.10
If you're looking for the corresponding u-boot that would be on git.ti.com. We use gitorious there so I can give you a nice easy link to download a tarball in that case:
http://git.ti.com/ti-u-boot/ti-u-boot/archive-tarball/ti-u-boot-2013.01.01-amsdk-05.07.00.00
Of course it's generally better to actually do the full clone so that you can have access to all the commit logs, etc.