tpm: Remove tpm_show_caps_1_2

The version of the TPM should not depend on the bus it is connected
through. 1.1, 1.2 and soon 2.0 TPMS will be all be able to use the
same bus interfaces.

Make tpm_show_caps try the 1.2 capability first. If that fails then
fall back to the 1.1 capability. This effectively auto-detects what
interface the TPM supports at run-time.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>