iotests: Select a default machine for the rx and avr targets

If you are building only with either the new rx-softmmu or avr-softmmu
target, "make check-block" fails a couple of tests since there is no
default machine defined in these new targets. We have to select a machine
in the "check" script for these, just like we already do for the arm- and
tricore-softmmu targets.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <20200722161908.25383-1-thuth@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

tests/qemu-iotests/check

@@ -595,15 +595,19 @@ then
 fi
 export QEMU_PROG="$(type -p "$QEMU_PROG")"
 
+export QEMU_OPTIONS="-nodefaults -display none -accel qtest"
 case "$QEMU_PROG" in
     *qemu-system-arm|*qemu-system-aarch64)
-        export QEMU_OPTIONS="-nodefaults -display none -machine virt -accel qtest"
+        export QEMU_OPTIONS="$QEMU_OPTIONS -machine virt"
         ;;
-    *qemu-system-tricore)
-        export QEMU_OPTIONS="-nodefaults -display none -machine tricore_testboard -accel qtest"
+    *qemu-system-avr)
+        export QEMU_OPTIONS="$QEMU_OPTIONS -machine mega2560"
+        ;;
+    *qemu-system-rx)
+        export QEMU_OPTIONS="$QEMU_OPTIONS -machine gdbsim-r5f562n8"
         ;;
-    *)
-        export QEMU_OPTIONS="-nodefaults -display none -accel qtest"
+    *qemu-system-tricore)
+        export QEMU_OPTIONS="-$QEMU_OPTIONS -machine tricore_testboard"
         ;;
 esac