tpm/st33zp24: Remove useless tpm_gen_interrupt

This function should only be called as part of an IRQ probing protocol
and st33 does not have any code to detect that the IRQ it tries to
generate was not generated and disable the IRQ.

Since st33 is primarily a DT binding driver it should not be doing
IRQ probing anyhow, so let us just delete this useless call.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>