bootstage: Plumb in bootstage calls for basic operations

This inserts bootstage calls into tftp, usb start and bootm. We
could go further, but this is a reasonable start to illustrate
the concept.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/net/bootp.c b/net/bootp.c
index 34124b8..9e32476 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -322,6 +322,7 @@
 		BootpVendorProcess((uchar *)&bp->bp_vend[4], len);
 
 	NetSetTimeout(0, (thand_f *)0);
+	bootstage_mark_name(BOOTSTAGE_ID_BOOTP_STOP, "bootp_stop");
 
 	debug("Got good BOOTP\n");
 
@@ -589,6 +590,7 @@
 	Bootp_t *bp;
 	int ext_len, pktlen, iplen;
 
+	bootstage_mark_name(BOOTSTAGE_ID_BOOTP_START, "bootp_start");
 #if defined(CONFIG_CMD_DHCP)
 	dhcp_state = INIT;
 #endif
@@ -949,6 +951,8 @@
 			BootpCopyNetParams(bp); /* Store net params from reply */
 			dhcp_state = BOUND;
 			printf ("DHCP client bound to address %pI4\n", &NetOurIP);
+			bootstage_mark_name(BOOTSTAGE_ID_BOOTP_STOP,
+					    "bootp_stop");
 
 			net_auto_load();
 			return;