dmaengine: sh: rz-dmac: Remove unused rz_dmac_chan.*_word_size

The src_word_size and dst_word_size members of the rz_dmac_chan
structure were never used, so they can be removed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/021bdf56f1716276a55bcfb1ea81bba5f1d42b3d.1679910274.git.geert+renesas@glider.be


Signed-off-by: Vinod Koul <vkoul@kernel.org>