seabios: turn off CONFIG_ATA_DMA

There have been regressions reported, when booting FreeDOS.
https://www.mail-archive.com/qemu-devel@nongnu.org/msg593254.html

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

roms/config.seabios-128k

@@ -2,7 +2,7 @@
 # need to turn off features (xhci,uas) to make it fit into 128k
 CONFIG_QEMU=y
 CONFIG_ROM_SIZE=128
-CONFIG_ATA_DMA=y
+CONFIG_ATA_DMA=n
 CONFIG_BOOTSPLASH=n
 CONFIG_XEN=n
 CONFIG_USB_OHCI=n

roms/config.seabios-256k

@@ -1,4 +1,4 @@
 # for qemu machine types 2.0 + newer
 CONFIG_QEMU=y
 CONFIG_ROM_SIZE=256
-CONFIG_ATA_DMA=y
+CONFIG_ATA_DMA=n