Previously, if a TIR Schedule is passed to `tvm.lower`, the error
message is returned `ValueError: ('Expected input to be an IRModule,
PrimFunc or Schedule, but got, ', <class
'tvm.tir.schedule.schedule.Schedule'>)`. This can cause user
confusion, as the expected class name in the error message does not
differentiate between between a `tvm.te.Schedule` and a
`tvm.tir.Schedule`. Updated error message to explicitly state that
this should be a `te.Schedule`.
Eric Lunderberg
45568c9963