Properly format linux-arm64ilp32 target config

Otherwise the ./config script fails with errors like:

> Operating system: x86_64-whatever-linux2
> This system (linux-x86_64) is not supported. See file INSTALL for details.

The failure was introduced by a93d3e06

.

RT#4062

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>