meson: convert tests/qtest to meson

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/tests/qtest/boot-serial-test.c b/tests/qtest/boot-serial-test.c
index bfe7624..b6b1c23 100644
--- a/tests/qtest/boot-serial-test.c
+++ b/tests/qtest/boot-serial-test.c
@@ -14,7 +14,7 @@
  */
 
 #include "qemu/osdep.h"
-#include "libqtest.h"
+#include "libqos/libqtest.h"
 #include "libqos/libqos-spapr.h"
 
 static const uint8_t bios_avr[] = {