ata: ahci: Don't cap AHCI port count under CONFIG_DM_SCSI

When using device model this sort of hardcoded limits aren't used or
necessary.

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 333f045..5fafb63 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -230,8 +230,10 @@
 	debug("cap 0x%x  port_map 0x%x  n_ports %d\n",
 	      uc_priv->cap, uc_priv->port_map, uc_priv->n_ports);
 
+#if !defined(CONFIG_DM_SCSI)
 	if (uc_priv->n_ports > CONFIG_SYS_SCSI_MAX_SCSI_ID)
 		uc_priv->n_ports = CONFIG_SYS_SCSI_MAX_SCSI_ID;
+#endif
 
 	for (i = 0; i < uc_priv->n_ports; i++) {
 		if (!(port_map & (1 << i)))