drivers: wireless: Add retry sequence in gs2200m_send_cmd()

Summary:
- This commit is a workaround to avoid errors in gs2200m_send_cmd()
- See the actual sequence in Testing for details

Impact:
- gs2200m driver

Testing:
- Test with spresense:wifi
- 1-1 Run tcpclient on NuttX and run nc on Linux
- 1-2 Stop nc on Linux then tcpclient also stops
- 1-3 Run tcpclient then the first AT+NCTCP will fail
- 1-4 But the second AT+NCTCP will succeed
- 2-1 Run tcpclient on NuttX and run nc on Linux
- 2-2 Stop nc on Linux then tcpclient also stops
- 2-3 Run tcpserver then the first AT+NSTCP will fail
- 2-4 But the second AT+NSTCP will succeed

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

drivers/wireless/gs2200m.c

@@ -1450,6 +1450,7 @@ static enum pkt_type_e gs2200m_send_cmd(FAR struct gs2200m_dev_s *dev,
 {
   enum spi_status_e s;
   enum pkt_type_e r = TYPE_SPI_ERROR;
+  int n = 1;
 
   /* Disable gs2200m irq to poll dready */
 
@@ -1457,6 +1458,8 @@ static enum pkt_type_e gs2200m_send_cmd(FAR struct gs2200m_dev_s *dev,
 
   wlinfo("+++ cmd=%s", cmd);
 
+retry:
+
   s = gs2200m_hal_write(dev, cmd, strlen(cmd));
   r = _spi_err_to_pkt_type(s);
 
@@ -1467,6 +1470,22 @@ static enum pkt_type_e gs2200m_send_cmd(FAR struct gs2200m_dev_s *dev,
 
   r = gs2200m_recv_pkt(dev, pkt_dat);
 
+  /* NOTE: retry in case of errors */
+
+  if ((TYPE_OK != r) && (0 <= --n))
+    {
+      if (pkt_dat)
+        {
+          /* release & initialize pkt_dat before retry */
+
+          _release_pkt_dat(dev, pkt_dat);
+          memset(pkt_dat, 0, sizeof(pkt_dat));
+        }
+
+      wlwarn("*** retry cmd=%s (n=%d) \n", cmd, n);
+      goto retry;
+    }
+
 errout:
 
   /* Enable gs2200m irq again */