[PATCHES v2] Add more i.MX6UL/ULL support

[Christian Mauderer]

Hello,

this patches are an update for

https://lists.rtems.org/pipermail/devel/2020-April/058863.html

The RTEMS and docs patch is rebased to the current master.

The libbsd patches are adapted to have the right order and include the
changes like discussed. This version is for the 5-freebsd-12 branch.
I'll adapt them for libbsd master and push them together as soon as I
have a go.

Best regards

Christian