NRF52840 : Compilation error while building Bare-Metal BLE Application using mbed-os-6.4.0,

I upgraded the version of my BLE Application from mbed-os-5.15.5 to mbed-os-6.4.0. I am building my application as a bare-metal application and I get the error below. I am not sure why the errors below are occurring, since I never set these values when I compiled it using mbed-os-5.15.5 and code where the compilation errors occur I suppose always used the BLE Cordio Defaults prior to this version of the mbed-os, unless I need to set some values specific to my application in mbed_app.json?

FYI, the application compiles without any issues under mbed-os-5.15.5.

[Error] cfg_stack.c@69,2: #error "CORDIO_CFG_DESIRED_ATT_MTU value is outside valid range"
[Error] cfg_stack.c@76,3: 'MBED_CONF_CORDIO_DESIRED_ATT_MTU' undeclared here (not in a function)
[Error] cfg_stack.c@78,3: 'MBED_CONF_CORDIO_MAX_PREPARED_WRITES' undeclared here (not in a function)
[ERROR] .\mbed-os\connectivity\FEATURE_BLE\libraries\cordio_stack\ble-host\sources\stack\cfg\cfg_stack.c:69:2: error: #error "CORDIO_CFG_DESIRED_ATT_MTU value is outside valid range"
   69 | #error "CORDIO_CFG_DESIRED_ATT_MTU value is outside valid range"
      |  ^~~~~
.\mbed-os\connectivity\FEATURE_BLE\libraries\cordio_stack\ble-host\sources\stack\cfg\cfg_stack.c:76:3: error: 'MBED_CONF_CORDIO_DESIRED_ATT_MTU' undeclared here (not in a function)
   76 |   MBED_CONF_CORDIO_DESIRED_ATT_MTU,    /* desired ATT MTU */
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\mbed-os\connectivity\FEATURE_BLE\libraries\cordio_stack\ble-host\sources\stack\cfg\cfg_stack.c:78:3: error: 'MBED_CONF_CORDIO_MAX_PREPARED_WRITES' undeclared here (not in a function)
   78 |   MBED_CONF_CORDIO_MAX_PREPARED_WRITES /* number of queued prepare writes supported by server */

Thanks,
Ajay