Make r4.5 and older boards work again

For the DRV8323 used on r4.5 and older, the enable line shouldn't be
read until after the enable sequence is completed.  We just do that
everywhere to make things safer.

fw/drv8323.cc

@@ -428,7 +428,7 @@ void Drv8323::Power(bool value) { impl_->Power(value); }
 
 bool Drv8323::fault() {
   return impl_->status_.fault_config ||
-      ((impl_->enable_.read() != 0) &&
+      ((impl_->enable_state_ == kEnabled) &&
        ((g_measured_hw_family == 0 && g_measured_hw_rev == 3) ?
         // This revision seems to be unable to read the fault line
         // properly.  Thus we get a laggier version over SPI.