tests/tcg: fixup Aarch64 semiconsole test

We need to ensure we squash the serial port if we want to hand craft
our muxed input. As a bonus emit the example with a V=1 build to make
it easier for people to figure out.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231120150833.2552739-7-alex.bennee@linaro.org>

tests/tcg/aarch64/Makefile.softmmu-target

@@ -48,10 +48,11 @@ QEMU_BASE_MACHINE=-M virt -cpu max -display none
 QEMU_OPTS+=$(QEMU_BASE_MACHINE) -semihosting-config enable=on,target=native,chardev=output -kernel
 
 # console test is manual only
-QEMU_SEMIHOST=-chardev stdio,mux=on,id=stdio0 -semihosting-config enable=on,chardev=stdio0 -mon chardev=stdio0,mode=readline
-run-semiconsole: QEMU_OPTS=$(QEMU_BASE_MACHINE) $(QEMU_SEMIHOST)  -kernel
+QEMU_SEMIHOST=-serial none -chardev stdio,mux=on,id=stdio0 -semihosting-config enable=on,chardev=stdio0 -mon chardev=stdio0,mode=readline
+run-semiconsole: QEMU_OPTS=$(QEMU_BASE_MACHINE) $(QEMU_SEMIHOST) -kernel
 run-semiconsole: semiconsole
 	$(call skip-test, $<, "MANUAL ONLY")
+	$(if $(V),@printf "  %-7s %s %s\n" "TO RUN" $(notdir $(QEMU)) "$(QEMU_OPTS) $<")
 run-plugin-semiconsole-with-%: semiconsole
 	$(call skip-test, $<, "MANUAL ONLY")