tcl/target: add lpc8xx.cfg

This adds a trivial config for LPC8xx chips based on the already
existing infrastructure in lpc1xxx.cfg.

Change-Id: I7384df1f3c2e3e8ab767319728db5c4f8149480f
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/2464


Tested-by: jenkins
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Nemui Trinomius <nemuisan_kawausogasuki@live.jp>