loraping: remove bootloader/mgmt dependencies
loraping: remove bootloader/mgmt dependencies

Some dependencies don't seem necessary for this sample app, and removing
them allows for use in constrained devices (eg, b-l072z-lrwan1 with 72K
slots).

Signed-off-by: Fabio Utzig <66676b1ceaf93296e098708c09494361103aa635@apache.org>

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