qemu: capabilities: Move setting QEMU_CAPS_DEVICE_VIDEO_PRIMARY to virQEMUCapsInitQMP...

qemu: capabilities: Move setting QEMU_CAPS_DEVICE_VIDEO_PRIMARY to virQEMUCapsInitQMPBasicArch

Until we clean up and remove all capabilities which no longer make sense
to have separately, we should use virQEMUCapsInitQMPBasicArch to set the
defaults as it's used by qemuxml2argvtest when testing with fake
capabilities.

This allows us to prevent testing dead code paths with the fake
capability tests.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>