i3c: renesas: Don't register devices when ENTDAA times out

renesas_i3c_daa() derives the number of newly assigned dynamic addresses
from cmd->rx_count, which the response ISR sets to the number of address
slots ENTDAA left unassigned. It starts out as zero, which already means
"every address was assigned", so a timed out transfer leaves that value
in place and it gets used as a result.

On a bus with no target connected the ENTDAA times out and the driver
registers RENESAS_I3C_MAX_DEVS devices that are not there, each costing
the core two seconds on a GETPID that can only time out:

  i3c i3c-0: Failed to add I3C device at address 9, error -110
  ...
  i3c i3c-0: Failed to add I3C device at address 16, error -110

Start from maxdevs instead: no address is assigned before ENTDAA runs,
and the existing rx_count >= maxdevs check then reports an empty bus.

Fixes: d028219a9f ("i3c: master: Add basic driver for the Renesas I3C controller")
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> # on RZ/G3S
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260731070150.2519825-1-tommaso.merciai.xr@bp.renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/i3c/master/renesas-i3c.c

@@ -684,7 +684,7 @@ static int renesas_i3c_daa(struct i3c_master_controller *m)
 
 	init_completion(&xfer->comp);
 	cmd = xfer->cmds;
-	cmd->rx_count = 0;
+	cmd->rx_count = i3c->maxdevs;
 
 	PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(i3c->dev, pm);
 	ret = PM_RUNTIME_ACQUIRE_ERR(&pm);