Add new start and read functions to support rk3588 device.
Also, add a device compatible string for the same.

Signed-off-by: Simon Xue <xxm@rock-chips.com>
Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>