devif_poll: only call the corresponding xxx_poll when there is data to be sent

reduce the execution consumption of irrelevant code

testing the TX rates of TCP and UDP based on the Infineon board can
increase them by 13%.

Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>

include/nuttx/net/netdev.h

@@ -411,6 +411,10 @@ struct net_driver_s
 
   net_ipv6addr_t d_ipv6draddr;  /* Default router IPv6 address */
 #endif /* CONFIG_NET_IPv6 */
+  uint32_t d_polltype;          /* The collection of protocols that need to
+                                 * be processed in devif_poll
+                                 */
+
   /* This is a new design that uses d_iob as packets input and output
    * buffer which used by some NICs such as celluler net driver. Case for
    * data input, note that d_iob maybe a linked chain only when using