drm/msm: dump a rd GPUADDR header for all buffers in the command

Currently the rd dump avoids any buffers marked as WRITE under
the assumption that the contents are not interesting.  While it
is true that the contents are uninteresting we should still print
the iova and size for all buffers so that any listening replay
tools can correctly construct the submission.

Print the header for all buffers but only dump the contents for
buffers marked as READ.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>