radv: set WD_SWITCH_ON_EOP=1 when drawing primitives from a stream output buffer

radv: set WD_SWITCH_ON_EOP=1 when drawing primitives from a stream output buffer

According to RadeonSI, this seems to be required by the hardware
to avoid GPU hangs. I think I just forgot to set that bit when I
implemented VK_EXT_transform_feedback.

This fixes a GPU hang with Space Engineers and DXVK.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110291
Fixes: b4eb029062a ("radv: implement VK_EXT_transform_feedback")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>