drm/msm: Fix %d vs %u

In debugging fence rollover, I noticed that GPU state capture and
devcore dumps were showing me negative fence numbers.  Let's fix that
and some related signed vs unsigned confusion.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/489621/
Link: https://lore.kernel.org/r/20220615163532.3013035-1-robdclark@gmail.com