tests/functional: Convert the xtensa lx60 Avocado test

Use the new launch_kernel function to convert this test in a simple way.

Message-ID: <20240919185749.71222-4-thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 7f7f4c2..a75d6ba 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1915,6 +1915,7 @@
 F: hw/xtensa/xtfpga.c
 F: hw/net/opencores_eth.c
 F: include/hw/xtensa/mx_pic.h
+F: tests/functional/test_xtensa_lx60.py
 
 Devices
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