doc: add new SWX pipeline type to release notes
doc: add new SWX pipeline type to release notes

Add the new SWX pipeline type to the release notes.

Signed-off-by: Cristian Dumitrescu <25468b8a3698eeb3c368247f8635924bb4a1ce2c@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk