Undef byte swapping macros that exist in some envs.
Undef byte swapping macros that exist in some envs.

This allows the nimble unit tests to compile in sim on my linux machine.

X-Original-Commit: 849ca1da91eadc739c845b00f329ce4ad8ab6e97

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble