Sample type IO does not work if the triggering signal has small and uppercase letters

[vlahtin]

Due to the vicinity to the tape-out, I do not want to update the spice module to the latest release just in case. But here is how to replicate it:
_=spice_iofile(self,name=f'IDATA_OUT0',dir='out',iotype='sample',trigger=f'io_OUTCLK',vth=self.vdd/2,edgetype='falling',ionames=f'io_IDATA_OUT0<9:0>',ioformat='dec')

For some reason the IO name is forced to uppercase, but not enforced throughout, causing the error.

If you have cycles, please fix @alttiheikkinen @sporrasm