ata: libahci: use ahci_nr_ports() helper

Use ahci_nr_ports() helper instead of open coding the same.

No functional change.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>

Author: floatious

drivers/ata/libahci.c

@@ -2636,7 +2636,7 @@ void ahci_print_info(struct ata_host *host, const char *scc_s)
 		,
 
 		hweight32(impl),
-		(cap & 0x1f) + 1,
+		ahci_nr_ports(cap),
 		impl);
 
 	dev_info(host->dev,