Assign additional vendor specific elements for early HE testing

Assign additional vendor specific elements for early HE testing

These elements can be used for pre-standard publication testing of HE
before P802.11ax draft assigns the element ID extension. The payload of
these vendor specific elements is defined by the latest P802.11ax draft.
Please note that the draft is still work in progress and the element
payload is subject to change.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>