arch posix/native: Let's make use of new split native simulator if

Let's make it possible to use the newly introduced definitions
for separated sub-sections for .data and .text symbols in the
NATIVE_SIMULATOR_IF (symbols visible to the runner and other
images).
Note all symbols anothed like before with just
NATIVE_SIMULATOR_IF will keep next to .text just like before.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>