Fix extended key usage value while generating CSR

At present extended key usage values are added as
key usage values while generating CSR fixed the same.

Tested:
Verified that key usage and extended key usage values are
displayed properly

[devenrao]$ openssl req -text -in n1.csr
Certificate Request:
    Data:
        Version: 1 (0x1)
        Subject: subjectAltName=an.com/subjectAltName=bm.com, L=NJ,
CN=w3.ibm.com/name=cp, C=US/emailAddress=abc.com,
GN=gn/initials=in/algorithm=EC/extendedKeyUsage=ServerAuthentication/keyUsage=KeyCertSign/keyUsage=DigitalSignature,
O=IBM, ST=NY, SN=sn/unstructuredName=un
        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey

Signed-off-by: Marri Devender Rao <devenrao@in.ibm.com>
Change-Id: I80e2f82696a695ea551cbb01f6a0fd5a2a416663
diff --git a/certs_manager.hpp b/certs_manager.hpp
index 355840d..da47d35 100644
--- a/certs_manager.hpp
+++ b/certs_manager.hpp
@@ -198,6 +198,12 @@
     void addEntry(X509_NAME* x509Name, const char* field,
                   const std::string& bytes);
 
+    /** @brief Check if usage is extended key usage
+     *  @param[in] usage - key usage value
+     *  @return true if part of extended key usage
+     */
+    bool isExtendedKeyUsage(const std::string& usage);
+
     /** @brief Create CSR D-Bus object by reading the data in the CSR file
      *  @param[in] statis - SUCCESSS/FAILURE In CSR generation.
      */