arch/xtensa: Don't dump unsupported backtraces with call0

The backtrace mechanism is specific to the windowed call ABI
currently, so doesn't work with call0.  This was hidden previously
because backtraces were disabled by default at the kconfig level for
the old ("sample_controller") qemu_xtensa, but are on now with dc233c
for essentially arbitrary reasons.  There was some protection against
this already, extend it to the case where "we have windows, but aren't
using them".

Signed-off-by: Andy Ross <andyross@google.com>

Author: andyross

arch/xtensa/core/fatal.c

@@ -104,7 +104,7 @@ void z_xtensa_fatal_error(unsigned int reason, const z_arch_esf_t *esf)
 		coredump(reason, esf, IS_ENABLED(CONFIG_MULTITHREADING) ? k_current_get() : NULL);
 
 #if defined(CONFIG_XTENSA_ENABLE_BACKTRACE)
-#if XCHAL_HAVE_WINDOWED
+#if XCHAL_HAVE_WINDOWED && !defined(CONFIG_XTENSA_CALL0_ABI)
 		z_xtensa_backtrace_print(100, (int *)esf);
 #endif
 #endif