drm/msm/a6xx: Update ROQ size in coredump

Since RoQ size differs between generations, calculate dynamically the
RoQ size while capturing coredump.

Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/515610/
Link: https://lore.kernel.org/r/20221221203925.v2.4.I07f22966395eb045f6b312710f53890d5d7e69d4@changeid
Signed-off-by: Rob Clark <robdclark@chromium.org>