fetching the chip firmware version toward the end of the chip
anx74xx_tcpm_init() sequence is a good place to do this. we need this
info in any case and this is a safe place to access device registers
and cache the values. subsequent chip firmware queries typically
return the cached value. also, tcpci_tcpm_init() is already
structured this way.
TEST=verified with follow-up CL that firmware update succeeds and new
version is reported
BRANCH=none
BUG=b:35586895
Change-Id: Ic3fd07bbf8a220bfd506d59d8a1f3ea25b14e94c
Signed-off-by: Caveh Jalali <caveh@google.com>
Reviewed-on: https://chromium-review.googlesource.com/634513
Reviewed-by: Shawn N <shawnn@chromium.org>