CHROMIUM: tpm: fix potential deadlock in resume_if_needed

CHROMIUM: tpm: fix potential deadlock in resume_if_needed

Fixes potential deadlock in this call sequence:
    transmit_cmd -> resume_if_needed -> tpm_continue_selftest -> transmit_cmd

Sequence is now:
    transmit_cmd -> resume_if_needed -> tpm_continue_selftest -> tpm_transmit

Reorders declarations of transmit_cmd, tpm_continue_selftest, etc so
we don't need forward declarations of functions.

BUG=none
TEST=code review found the issue. No test.

Change-Id: I95aeb69e89faa2a6c6491350e49bd46ac44f06b1
Signed-off-by: Grant Grundler <grundler@chromium.org>