kvm_on_sigbus() and kvm_on_sigbus_vcpu() prototypes don't have
to be target specific. Remove this limitation to be able to build
softmmu/cpus.c once for all targets.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-7-f4bug@amsat.org>