This commit updates the uVisor libraries following the following fix:
* ARMmbed/uvisor@767e794 "K64F vMPU: Use the MPU fault address"
The bug made some release builds of the uVisor example halt because of
an imprecise bus fault not correctly handled by uVisor internally.
The change only affects targets where `FEATURE_UVISOR` and
`UVISOR_SUPPORTED` are defined.