serial: Fix armv7

Signed-off-by: Lukas Humbel <lukas.humbel@inf.ethz.ch>

hake: enable library dependencies on all platforms

Signed-off-by: Lukas Humbel <lukas.humbel@inf.ethz.ch>

armv7: Enable serial driver on pandaboard

Signed-off-by: Lukas Humbel <lukas.humbel@inf.ethz.ch>

ARM: move the *_map.h files into /include/maps/

Signed-off-by: Reto Achermann <reto.achermann@inf.ethz.ch>

flounder: making const pointers in receiving handlers, using CONST_CAST as a temporary solution in few places but finally it should be removed

Signed-off-by: Adam Turowski <adam.turowski@inf.ethz.ch>

ARMv7: Rewrote serial drivers on ARM.

They're now fairly well compartmentalised on both ARM and x86, and can start
automatically from Kaluga. There's also a 'kernel' serial driver, which uses
the syscall interface to read and write on the kernel console. This avoids
having user level and kernel code racing on access to the UART. Fish works
(minus line editing) on all Versatile Express platforms.

Signed-off-by: David Cock <david.cock@inf.ethz.ch>