SIM speed enhancement re-enabled and made configurable TI's original code supported SIM speed enhancement, but Openmoko had it disabled, and OM's disabling of speed enhancement somehow caused certain SIM cards to start working which didn't work before (OM's bug #666). Because our FC community is much smaller in year 2020 than OM's community was in their day, we are not able to find one of those #666-affected SIMs, thus the real issue they had encountered remains elusive. Thus our solution is to re-enable SIM speed enhancement and simply wait for if and when someone runs into a #666-affected SIM once again. We provide a SIM_allow_speed_enhancement global variable that allows SIM speed enhancement to be enabled or disabled per session, and an /etc/SIM_spenh file in FFS that allows it to enabled or disabled on a non-volatile basis. SIM speed enhancement is now enabled by default.