tpm: Add support for new Infineon I2C TPM (SLB 9645 TT 1.2 I2C)

Add support for Infineon's new SLB 9645 TT 1.2 I2C TPMs,
which supports clockstretching, combined reads and a bus speed of
up to 400khz. The device also has a new device id.

This is based on the kernel patch provided by Infineon :
https://gerrit.chromium.org/gerrit/42332



Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Tom Wai-Hong Tam <waihong@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>