[Documentation] README section on out-of-tree build is confusing

The `README.md` contains three sections how to build the driver a) in-tree, b) as an out-of-tree module or c) with DKMS. [The section for an out-of-tree module built](https://github.com/intel/ipu6-drivers?tab=readme-ov-file#2-build-outside-kernel-source-tree) is confusing, because the 3rd bullet point states that the kernel sources must be patched.

Is this a copy-&-paste error from the previous section for an in-tree built? For an out-of-tree built the original kernel sources shouldn't be required, hence it doesn't make sense to patch them.