Disable AFALG when cross-compiling
Disable AFALG when cross-compiling

We don't currently support cross-compiling of the afalg engine. However
we were failing to explicitly mark it as disabled during Configure leading
to a failed build.

Reviewed-by: Richard Levitte <5fb523282dd7956571c80524edc2dccfa0bd8234@openssl.org>

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl