module_allow_arch() is the single target-specific call in the
whole vl.c file. Move the module initialization out to arch_init.c,
that way we'll be able to build vl.o once for all targets (the
next commit).

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-21-f4bug@amsat.org>