6loWPAN: Local MAC address is fixed by the configuration.  The remote address be with short or extended.

wireless/ieee802154:  Simplifies some primitive prototypes

Approved-by: Gregory Nutt <gnutt@nuttx.org>

This reverts commit 1e054a2d.

Merged in david_s5/nuttx-15/david_s5/fixed-typo-and-backward-ifdef-1493853031502 (pull request #345)

Fixed typo and backward ifdef

Approved-by: Gregory Nutt <gnutt@nuttx.org>

wireless/ieee802154: Starts work on setting PIB attributes

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Ieee802154

Approved-by: Gregory Nutt <gnutt@nuttx.org>

6loWPAN: Changes to use new MAC interfaces.  Incomplete and needs some clean-up of dangling, unused definitions.

6loWPAN: Add basic call path to interface with the MAC layer through the MAC network driver.  Logic has not yet been implemented.  This is just a structural change in preparation for additional changes.