Platform: nordic: unify target configuration

unify target configuration for nrf53, nrf91, and laird.

Combining these three source files into a single file makes it easier
to make changes as patches don't need to be applied three times.

Change-Id: I3c0db861b8db9981552b689e298b525918afff36
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
8 files changed