drm/msm/dpu: drop the `id' field from DPU_HW_SUBBLK_INFO

The field `id' is not used for subblocks. The handling code usually
knows, which sub-block it is now looking at. Drop the field completely.

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/570100/
Link: https://lore.kernel.org/r/20231201234234.2065610-5-dmitry.baryshkov@linaro.org