Fix for changing BIOS AdminPassword through BMC

BIOS hash value doesn't match with BMC computed hash value
for changing admin password

Changed the hash function as per BIOS usage to match with
BMC computed hash value and BIOS hash value

Tested:
By giving POST to
'/redfish/v1/Systems/system/Bios/Actions/Bios.ChangePassword'
Body:
{
 "NewPassword": "123456789",
 "OldPassword": "1234567890",
 "PasswordName": "AdminPassword"
}
Response: Success

Signed-off-by: Snehalatha Venkatesh <snehalathax.v@intel.com>
Change-Id: Ibaf0079e471914b738f167652d6b985533f5d920
diff --git a/include/password.hpp b/include/password.hpp
index 3156a4e..8d4e00e 100644
--- a/include/password.hpp
+++ b/include/password.hpp
@@ -39,6 +39,7 @@
 constexpr uint8_t maxHashSize = 64;
 constexpr uint8_t maxSeedSize = 32;
 constexpr uint8_t maxPasswordLen = 32;
+constexpr int iterValue = 1000;
 
 using Base = sdbusplus::xyz::openbmc_project::BIOSConfig::server::Password;
 namespace fs = std::filesystem;
@@ -76,8 +77,6 @@
                         std::string newPassword) override;
 
   private:
-    uint8_t convertUnicode(const std::string& pwd,
-                           std::array<uint16_t, maxPasswordLen>& unicodePwd);
     void verifyPassword(std::string userName, std::string currentPassword,
                         std::string newPassword);
     bool isMatch(const std::array<uint8_t, maxHashSize>& expected,