Oracle Cloud Adapter for Salesforce.com is available only in Oracle SOA Suite 11g
Refer the following document for the same
1.2.2 Oracle SOA versions
Oracle Cloud Adapter for Salesforce.com is available on 22.214.171.124 (PS6) onwards and 12C (12.1.3).
To make a use of Salesforce adapter you need to upgrade SOA to PS6 and the apply Opatch for Salesforce Adapter.