vulkan/wsi/x11: handle timeouts properly in next image acquire (v1.1)

vulkan/wsi/x11: handle timeouts properly in next image acquire (v1.1)

For 0 timeout, just poll for an event, and if none, return
For UINT64_MAX timeout, just wait for special event blocked
For other timeouts get the xcb fd and block on it, decreasing
the timeout if we get woken up for non-special events.

v1.1: return VK_TIMEOUT for poll timeouts.
handle timeout going negative.

Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>