acpi rom file loading: disable for QEMU 128K

It's only useful for QEMU 1.7 and newer.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/src/Kconfig b/src/Kconfig
index f753170..bf2ce1b 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -444,7 +444,7 @@
             If unsure, say Y.
     config FW_ROMFILE_LOAD
         bool "Load BIOS tables from ROM files"
-        depends on QEMU_HARDWARE
+        depends on QEMU_HARDWARE && !QEMU_128K
         default y
         help
             Support loading BIOS firmware tables from ROM files.