This fixes when configuring with --without-default-devices:

  $ qemu-system-mips64 -M malta --nodefaults -bios /dev/null
  qemu-system-mips64el: Unknown device 'vt82c686b-usb-uhci' for bus 'PCI'
  Aborted (core dumped)

  (gdb) bt
  #1  0x00007ffff5a2d895 in __GI_abort () at abort.c:79
  #2  0x00005555558745c3 in qdev_create (bus=bus@entry=0x55555623d160, name=name@entry=0x555555b13ee8 "vt82c686b-usb-uhci") at hw/core/qdev.c:131
  #3  0x00005555558cb3e1 in pci_create_multifunction (bus=bus@entry=0x55555623d160, devfn=devfn@entry=42, multifunction=multifunction@entry=false, name=name@entry=0x555555b13ee8 "vt82c686b-usb-uhci") at hw/pci/pci.c:2104
  #4  0x00005555558cb88b in pci_create_simple_multifunction (name=name@entry=0x555555b13ee8 "vt82c686b-usb-uhci", multifunction=false, devfn=devfn@entry=42, bus=bus@entry=0x55555623d160) at hw/pci/pci.c:2126
  #5  0x00005555558cb88b in pci_create_simple (bus=bus@entry=0x55555623d160, devfn=devfn@entry=42, name=name@entry=0x555555b13ee8 "vt82c686b-usb-uhci") at hw/pci/pci.c:2126
  #6  0x0000555555760d18 in vt82c686b_southbridge_init (slot=5, p_isa_bus=<synthetic pointer>, i2c_bus=<synthetic pointer>, intc=<optimized out>, pci_bus=0x55555623d160) at hw/mips/mips_fulong2e.c:243
  #7  0x0000555555760d18 in mips_fulong2e_init (machine=<optimized out>) at hw/mips/mips_fulong2e.c:348
  #8  0x000055555587bf2b in machine_run_board_init (machine=0x555555ffe430) at hw/core/machine.c:1030

Fixes: 7c28b925b7e
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/isa/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/isa/Kconfig b/hw/isa/Kconfig
index c942b47d03..1bb5ccdba7 100644
--- a/hw/isa/Kconfig
+++ b/hw/isa/Kconfig
@@ -35,6 +35,7 @@ config VT82C686
     bool
     select ISA_BUS
     select ACPI_SMBUS
+    select USB_UHCI
     select SERIAL_ISA
     select FDC
 
-- 
2.20.1