tpm: pay attention to IRQ info from PNP

If we discover the TIS TPM device via PNP, use the PNP IRQ information rather
than probing for an IRQ.  If PNP shows no IRQ, run the TPM in polling mode.

Tested-by:  <valdis.kletnieks@vt.edu>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Kylene Hall <kjhall@us.ibm.com>
Cc: <tpm@selhorst.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>