BACKPORT: dma-buf/fence: revert "don't wait when specified timeout is zero" (v2)

Reverts commit 847b19a3
	("dma-buf/fence: don't wait when specified timeout is zero")

When we don't call the wait function software signaling might never be
activated. This can cause infinite polling loops with unreliable interrupt
driven hardware.

v2: rebase on drm-next

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
  [sumits: reword commit msg for checkpatch warnings]
Link: http://patchwork.freedesktop.org/patch/msgid/1478553376-18575-2-git-send-email-alexander.deucher@amd.com


(cherry picked from commit 698c0f7ff21674ec08a4c6e99dd6da62fe5a344d)
Signed-off-by: Marissa Wall <marissaw@google.com>

Change-Id: I6a0d72034ecec3832c90864291bc5674da8a0b5d