Rename the 'usb-controller-explicit-(unavailable-)q35' test case to
'usb-controller-nec-xhci'. Since this also covers what
'usb-controller-xhci' was testing the latter is removed.
Other 'usb-xhci' test cases which were using the NEC controller are also
renamed to contain the name.
In case of 'usb-controller-qemu-xhci' the negative test case is deleted
as we don't need two cases for missing explicitly specified controller
and the positive case is modernized to use real capabilities.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>