o  Retrive the part number (CP2103 etc) from the hardware on attach. o  The CP2101 and CP2102 do not support GPIO pin use at all, enforce this. o  Support reading the GPIO status on the second port of the CP2105.  More    work is needed before the CP2105 GPIO pins can be used as outputs.
o  Retrive the part number (CP2103 etc) from the hardware on attach.
o  The CP2101 and CP2102 do not support GPIO pin use at all, enforce this.
o  Support reading the GPIO status on the second port of the CP2105.  More
   work is needed before the CP2105 GPIO pins can be used as outputs.

Hardware donated by:	Silicon Labs
MFC after:		3 weeks

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