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Test 2001 is obsolete.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)

qemu.mk

@@ -151,7 +151,7 @@ define run-help
 	@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

qemu_v8.mk

@@ -200,7 +200,7 @@ define run-help
 	@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