kernel/os: Fix os_dev list order
kernel/os: Fix os_dev list order

Contrary to what could be exepected from os_dev_add()
device list was sorted in incorrect order devices that should
be initialized first were added at the end of the list.

Even the reversed order could be further mismatched in following
scenario. List was in descending order:
3 3 3 1 1
Adding 2 would produce
3 3 3 1 2 1

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core