Will include architecture-specific properties about the kernel.
Currently they mainly hold macros for calculating where the kernel
starts and ends in physical and virtual memory.

Sometimes the VideoCore does not immediately provide the framebuffer
address, even after it has returned success via a mailbox read.

Otherwise, the serial sybsystem isn't initialized before the serial
drivers attempt to register themselves.

Create simple serial subsystem which makes use of initcalls, and convert
existing serial drivers to its use.

Handle comments better, add comment to target

the same place it was linked against.