Pull up following revision(s) (requested by tsutsui in ticket #1004):
sys/arch/luna68k/dev/siotty.c: revision 1.35
sys/arch/luna68k/dev/siotty.c: revision 1.36
sys/arch/luna68k/dev/siotty.c: revision 1.37
sys/arch/luna68k/dev/siotty.c: revision 1.38
sys/arch/luna68k/dev/lunaws.c: revision 1.25
sys/arch/luna68k/dev/lunaws.c: revision 1.26
sys/arch/luna68k/dev/lunaws.c: revision 1.27
sys/arch/luna68k/dev/siovar.h: revision 1.7
sys/arch/luna68k/dev/siotty.c: revision 1.34
struct device * -> device_t, use device_xname()  (from chs@)
Whitespace cleanup.
Use softint(9) to pass received data into wskbd(9) and wsmouse(9) layers.
It might be problematic to call them from an interrupt handler at IPL_SERIAL.
Tab/space cleanup.
Use softint(9) properly to process TX/RX data between tty(4) layer.
It could cause possible locking issue to call tty(4) layer functions
from IPL_SERIAL interrupt handlers.
Changes details (mostly similar to com(4) and z8530tty(4)):
- allocate RX buffer and put data and status into it in the interrupt handler
- call t_linesw->l_rint from the software interrupt handler
- set the only first byte in siottystart() and use t_outq buffer to send
  multiple TX data
- call the next t_linesw->l_start on TX complete in the software interrupt
  handler
Also put more changes:
- handle cnmagic(9) properly (now entering ddb(4) by console BREAK works)
- allocate tty in the attach function as other drivers rather than first open
- use proper variable types
Remove initialization of unused t_softc in struct tty (to make pullup easier).

(bouyer)