drm/msm/dpu: use devres-managed allocation for HW blocks

Use devm_kzalloc to create HW block structure. This allows us to remove
corresponding kfree and drop all dpu_hw_*_destroy() functions as well as
dpu_rm_destroy(), which becomes empty afterwards.

Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/570041/
Link: https://lore.kernel.org/r/20231201211845.1026967-7-dmitry.baryshkov@linaro.org