Quicksync doesn't do its work on the CPU, it does the work on the integrated GPU. Their processors that did not have on-board graphics did not have Quicksync support. See their P series and many of their Xeon parts which do not carry Quicksync support, while the versions with integrated graphics do have it.

AMD chips that have integrated GPUs (their APU series of chips) often do have support for hardware video encoders. Because, once again, its a function of the GPU and not the CPU.