hw: move display devices to hw/display/, configure via default-configs/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/default-configs/x86_64-softmmu.mak b/default-configs/x86_64-softmmu.mak
index 6fba70f..58b33cf 100644
--- a/default-configs/x86_64-softmmu.mak
+++ b/default-configs/x86_64-softmmu.mak
@@ -3,6 +3,7 @@
 include pci.mak
 include usb.mak
 CONFIG_VGA=y
+CONFIG_QXL=$(CONFIG_SPICE)
 CONFIG_VGA_PCI=y
 CONFIG_VGA_ISA=y
 CONFIG_VGA_CIRRUS=y