support/testing: usbip: wait for the keyboard be detected

Running TestUsbIp may fail when checking if two QEMU USB Keyboards are
reported by lsusb. On fast host, the second QEMU USB keyboard may not
aleady detected when lsusb is executed. So wait a bit, to let the new
keyboard be detected.

Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit 933a591d8a)
Signed-off-by: Titouan Christophe <titouan.christophe@mind.be>

support/testing/tests/package/test_usbip.py

@@ -1,4 +1,5 @@
 import os
+import time
 
 import infra.basetest
 
@@ -91,6 +92,9 @@ class TestUsbIp(infra.basetest.BRTest):
         # keyboard.
         self.assertRunOk("usbip attach --remote=127.0.0.1 --busid=1-1")
 
+        # Wait a bit, to let the new keyboard be detected.
+        time.sleep(1)
+
         # We check "lsusb" now sees exactly two QEMU USB Keyboards
         # (the original one, and a second one created by usbip).
         out, ret = self.emulator.run("lsusb")