drm/i915: Implement for_each_sgt_daddr_next

Implement a way to iterate over sgt with pre-initialized
sgt_iter state.

Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Oak Zeng <oak.zeng@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230926083742.14740-4-nirmoy.das@intel.com