First, remove unused macro and rs_multiport_struct structure. Nobody
uses them at all.
Further, the 2 drivers (they are below) which use the rest of
structures from serialP.h (async_struct and serial_state) do not use
all the members. Remove the members:
* which are unused or
* which are only initialized and never used for something real.
Everybody should avoid the structures with a looong distance.
Finally, remove the ALPHA kludge MCR quirks. They are 1:1 copy from
8250.h. No need to redefine them here.
The 2 promised users of the structures:
arch/ia64/hp/sim/simserial.c
drivers/tty/amiserial.c