Add machine files for bf60x including head files, Kconfig/Makefile and board
file.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBob Liu <lliubbo@gmail.com>

Each Blackfin port has been duplicating UART structures and defines when
there really is no need for it.  So start a new bfin_serial.h header to
unify all these pieces and give ourselves a fresh start.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>