sparc: disable floppy DMA

All functions relative to DMA (DMA_*() functions) are stubs on sparc platform.
Disable the DMA in the floppy controller, instead of calling these stubs.
Signed-off-by: NHervé Poussineau <hpoussin@reactos.org>
Message-id: 1453843944-26833-14-git-send-email-hpoussin@reactos.org
Signed-off-by: NJohn Snow <jsnow@redhat.com>

hw/block/fdc.c

@@ -2492,6 +2492,8 @@ static void sun4m_fdc_initfn(Object *obj)
     FDCtrlSysBus *sys = SYSBUS_FDC(obj);
     FDCtrl *fdctrl = &sys->state;
 
+    fdctrl->dma_chann = -1;
+
     memory_region_init_io(&fdctrl->iomem, obj, &fdctrl_mem_strict_ops,
                           fdctrl, "fdctrl", 0x08);
     sysbus_init_mmio(sbd, &fdctrl->iomem);