[PATCH] dz: Fixes to make it work

This a set of fixes mostly to make the driver actually work:

1. Actually select the line for setting parameters and receiver
   disable/enable.
2. Select the line for receive and transmit interrupt handling correctly.
3. Report the transmitter empty state correctly.
4. Set the I/O type of ports correctly.
5. Perform polled transmission correctly.
6. Don't fix the console line at ttyS3.
7. Magic SysRq support.
8. Various small bits here and there.

Tested with a DECstation 2100 (thanks Flo for making this possible).

[akpm@osdl.org: fix typo]
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>