drm/i915/guc: Record CTB info in error logs

When debugging GuC communication issues, it is useful to have the CTB
info available. So add the state and buffer contents to the error
capture log.

Also, add a sub-structure for the GuC specific error capture info as
it is now becoming numerous.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728022028.2190627-5-John.C.Harrison@Intel.com