doc: fix format in OpenSSL installation guide
doc: fix format in OpenSSL installation guide

List of supported OpenSSL versions and code block with dependencies were
not properly formatted.

Fixes: d61f70b4c918 ("crypto/libcrypto: add driver for OpenSSL library")
Cc: stable@dpdk.org

Signed-off-by: Andrea Grandi <859b2385320eb236fade25804ae52857448eb88a@intel.com>
Acked-by: Pablo de Lara <28355d9cfe41bb8148aea0fb24f47aae8f4217a1@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk