soc: mediatek: Use pkt_write function pointer for subsys ID compatibility
Switch to pkt_write and reg_write_mask function pointers for register
access, enabling compatibility with platforms regardless of subsys ID
support.
Signed-off-by: Jason-JH Lin <jason-jh.lin@mediatek.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>