net: ping: make do_ping() available via <net.h>

Make the do_ping() function in cmd/net.c a global one by getting rid of
the static qualifier, and move the prototype declaration from net-lwip.h
to net-common.h. This makes the function available to other parts of
U-Boot when CONFIG_NET=y, as was already the case when
CONFIG_NET_LWIP=y.

This is a peparation step to make the sandbox tests use a common API
between NET and NET_LWIP.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

cmd/net.c

@@ -456,8 +456,7 @@ static int netboot_common(enum proto_t proto, struct cmd_tbl *cmdtp, int argc,
 }
 
 #if defined(CONFIG_CMD_PING)
-static int do_ping(struct cmd_tbl *cmdtp, int flag, int argc,
-		   char *const argv[])
+int do_ping(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	if (argc < 2)
 		return CMD_RET_USAGE;