- In alps_tdlb7.c read SP8870 status reg to clear pending irqs in
   FE_SET_FRONTEND, as suggested by Ragnar Sundblad to avoid frontend
   hang-ups.
 - the vp310 support in mt312.c support should be configured to 90Mhz,
   too.  skystar2 driver with bugfixed master_xfer() should probably
   work now.