Adding a test if device key buffer has changed after calling to entropy func. this should enable as to eliminate some rare cases when the trng fail but still return success.
Adding a test if device key buffer has changed after calling to entropy func. this should enable as to eliminate some rare cases when the trng fail but still return success.

andcor02/mbed-os,kjbracey-arm/mbed,mbedmicro/mbed,kjbracey-arm/mbed,andcor02/mbed-os,andcor02/mbed-os,mbedmicro/mbed,andcor02/mbed-os,kjbracey-arm/mbed,mbedmicro/mbed,andcor02/mbed-os,mbedmicro/mbed,kjbracey-arm/mbed,andcor02/mbed-os,mbedmicro/mbed