busybox: use SHA-512 ($6$...) passsword encryption by default, like
the passwd program from the "shadow" package already does.

This allows for replacement of the "shadow" package by busybox
components at some time. It also prevents users from creating
uids with DES encryption which supports passwords only < 8 characters.
Move kernel patches to BSP layers

This should fix the build problems introduced by the vendor separation
commit.

This causes some code duplication, but the intention here is to have each BSP
overlay represent something that should live in a seperate vendor-managed
repository.

Placing the patches in the BSP layers makes them independent of other layers,
like openpli-oe-core itself.
Merge branch 'master' of git://git.code.sf.net/p/openpli/openpli-oe-core