nds32/board.c: add PCI prompt at boot up

add PCI prompt at boot up for probing PCI device

Signed-off-by: Macpaul Lin <macpaul@andestech.com>

arch/nds32/lib/board.c

@@ -365,6 +365,7 @@ void board_init_r(gd_t *id, ulong dest_addr)
 	env_relocate();
 
 #if defined(CONFIG_CMD_PCI) || defined(CONFIG_PCI)
+	puts("PCI:   ");
 	nds32_pci_init();
 #endif