The POSIX ARCH delegates some of the tasks which normally
are taken care of by the ARCH to the SOC or BOARD levels.
To avoid changes in the kernel-arch IF propagating into
the arch-soc and arch-board interfaces (which would break
off-tree posix boards) isolate them.
Also move arch inlined functions into the arch.h header,
and out from the headers which specify the posix arch-soc
and arch-board interfaces.
Signed-off-by: Alberto Escolar Piedras <alpi@oticon.com>