target/xtensa: make xtensa_modules static on import

xtensa_modules variable defined in each xtensa-modules.c.inc is only
used locally by the including file. Make it static.

Reported-by: Yury Gribov <tetra2005@gmail.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/xtensa/import_core.sh

@@ -35,6 +35,7 @@ tar -xf "$OVERLAY" -O binutils/xtensa-modules.c | \
         -e '/^#include "ansidecl.h"/d' \
         -e '/^Slot_[a-zA-Z0-9_]\+_decode (const xtensa_insnbuf insn)/,/^}/s/^  return 0;$/  return XTENSA_UNDEFINED;/' \
         -e 's/#include <xtensa-isa.h>/#include "xtensa-isa.h"/' \
+        -e 's/^\(xtensa_isa_internal xtensa_modules\)/static \1/' \
     > "$TARGET"/xtensa-modules.c.inc
 
 cat <<EOF > "${TARGET}.c"