drm/msm/adreno: fix gpu probe if no interconnect-names

If there is no interconnect-names, but there is an interconnects
property, then of_icc_get(dev, "gfx-mem"); would return an error
rather than NULL.

Also, if there is no interconnect-names property, there will never
be a ocmem path.  But of_icc_get(dev, "ocmem") would return -EINVAL
instead of -ENODATA.  Just don't bother trying in this case.

v2: explicity check for interconnect-names property

Fixes: 08af4769 ("drm/msm: handle for EPROBE_DEFER for of_icc_get")
Fixes: 00bb9243 ("drm/msm/gpu: add support for ocmem interconnect path")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>