Remove sio(4).

It had been disconnected from build in r181233 in 2008.

Reviewed by:	imp

sbin/comcontrol/comcontrol.8

@@ -54,7 +54,6 @@ dialout devices
 .El
 .Sh SEE ALSO
 .Xr stty 1 ,
-.Xr sio 4
 .Sh HISTORY
 Originally part of cgd's com package patches, version 0.2.1, to
 .Bx 386 0.1 .

sbin/conscontrol/conscontrol.8

@@ -101,7 +101,6 @@ This is an interface to the tty ioctl
 .Dv TIOCCONS .
 .El
 .Sh SEE ALSO
-.Xr sio 4 ,
 .Xr syscons 4 ,
 .Xr tty 4 ,
 .Xr vt 4 ,

sbin/reboot/boot_i386.8

@@ -36,7 +36,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 30, 2019
+.Dd November 19, 2019
 .Dt BOOT 8 i386
 .Os
 .Sh NAME
@@ -223,15 +223,6 @@ you can use the
 .Fl h
 option to force the kernel to use the serial port as its
 console device.
-The serial port driver
-.Xr sio 4
-(but not
-.Xr uart 4 )
-has a flag (0x20) to override this option.
-If that flag is set, the serial port will always be used as the console,
-regardless of the
-.Fl h
-option described here.
 .It Fl m
 mute the console to suppress all kernel console input and output during the
 boot.

share/man/man4/Makefile

@@ -461,7 +461,6 @@ MAN=	aac.4 \
 	siftr.4 \
 	siis.4 \
 	simplebus.4 \
-	sio.4 \
 	sis.4 \
 	sk.4 \
 	${_smartpqi.4} \

share/man/man4/rc.4

@@ -91,7 +91,6 @@ file can be consulted for more information.
 .Sh SEE ALSO
 .Xr tty 1 ,
 .Xr ttyname 3 ,
-.Xr sio 4 ,
 .Xr tty 4 ,
 .Xr device.hints 5 ,
 .Xr comcontrol 8 ,