fdc: Deprecate configuring floppies with -global isa-fdc

Deprecate

    -global isa-fdc.driveA=...
    -global isa-fdc.driveB=...

in favour of

    -device floppy,unit=0,drive=...
    -device floppy,unit=1,drive=...

Same for the other floppy controller devices.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Message-Id: <20200622094227.1271650-7-armbru@redhat.com>

docs/system/deprecated.rst

@@ -164,6 +164,32 @@ previously available ``-tb-size`` option.
 Use ``-display sdl,show-cursor=on`` or
  ``-display gtk,show-cursor=on`` instead.
 
+``Configuring floppies with ``-global``
+'''''''''''''''''''''''''''''''''''''''
+
+Use ``-device floppy,...`` instead:
+::
+
+    -global isa-fdc.driveA=...
+    -global sysbus-fdc.driveA=...
+    -global SUNW,fdtwo.drive=...
+
+become
+::
+
+    -device floppy,unit=0,drive=...
+
+and
+::
+
+    -global isa-fdc.driveB=...
+    -global sysbus-fdc.driveB=...
+
+become
+::
+
+    -device floppy,unit=1,drive=...
+
 QEMU Machine Protocol (QMP) commands
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