UPDATE:
The following functions:
extern bStatus_t SM_ResponderInit( void ) ,
extern bStatus_t GAP_PeriDevMgrInit( void ); and
extern bStatus_t GAP_SendSlaveSecurityRequest( uint16 connectionHandle, uint8 authReq ),
are probably located in the library files CC2540_BLE_cent.lib and CC254x_BLE_HCI_TL_None.lib.
I'm suspecting that something gets messed up with the definitions of these funtions, in the lib files, when linking a new project in the latest IAR Version.
Are there any updated lib files maybe?