Back up and restore config.h systematically
Back up and restore config.h systematically

In all.sh, always save config.h before running a component, instead of
doing it manually in each component that requires it (except when we
forget, which has happened). This would break a script that requires
config.h.bak not to exist, but we don't have any of those.

NXPmicro/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,NXPmicro/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls