soc: mediatek: mtk-cmdq: Extend cmdq_pkt_write API for SoCs without subsys ID

soc: mediatek: mtk-cmdq: Extend cmdq_pkt_write API for SoCs without subsys ID

This patch extends the cmdq_pkt_write API to support SoCs that do not
have subsys ID mapping by introducing new register write APIs:
- cmdq_pkt_write_pa() and cmdq_pkt_write_subsys() replace
  cmdq_pkt_write()
- cmdq_pkt_write_mask_pa() and cmdq_pkt_write_mask_subsys() replace
  cmdq_pkt_write_mask()

To ensure consistent function pointer interfaces, both
cmdq_pkt_write_pa() and cmdq_pkt_write_subsys() provide subsys and
pa_base parameters. This unifies how register writes are invoked,
regardless of whether subsys ID is supported by the device.

All GCEs support writing registers by PA (with mask) without subsys,
but this requires extra GCE instructions to convert the PA into a GCE
readable format, reducing performance compared to using subsys directly.
Therefore, subsys is preferred for register writes when available.

API documentation and function pointer declarations in cmdq_client_reg
have been updated. The original write APIs will be removed after all
CMDQ users transition to the new interfaces.

Signed-off-by: Jason-JH Lin <jason-jh.lin@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Acked-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>