qemu (ARMv7/v8): fix comment in qemu build script

Test 2001 is obsolete. xtest 1004 is a good candidate: load TA, invoke
and close.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey)
Tested-by: Joakim Bech <joakim.bech@linaro.org> (RPi3, MTK8173)
Tested-by: Etienne Carriere <etienne.carriere@linaro.org> (qemu_v7/v8)
diff --git a/qemu.mk b/qemu.mk
index 1ef153f..025dac9 100644
--- a/qemu.mk
+++ b/qemu.mk
@@ -151,7 +151,7 @@
 	@echo xtest
 	@echo
 	@echo To run a single test case replace the xtest command with for instance
-	@echo xtest 2001
+	@echo xtest 1004
 endef
 
 define launch-terminal
diff --git a/qemu_v8.mk b/qemu_v8.mk
index 7125bda..237d14e 100644
--- a/qemu_v8.mk
+++ b/qemu_v8.mk
@@ -200,7 +200,7 @@
 	@echo xtest
 	@echo
 	@echo To run a single test case replace the xtest command with for instance
-	@echo xtest 2001
+	@echo xtest 1004
 endef
 
 define launch-terminal