tpm tis: Do not print timeout messages twice

The tis driver does a tpm_get_timeouts out side of tpm_chip_register,
and tpm_get_timeouts can print a message, resulting in two prints, eg:

 tpm tpm0: [Hardware Error]: Adjusting reported timeouts: A 10000->750000us B 10000->2000000us C 10000->750000us D 10000->750000us

Keep track and prevent tpm_get_timeouts from running a second time, and
clarify the purpose of the call in tpm_tis_core to only be connected to
irq testing.

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>