anx3429: read chip firmware version during init

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>

driver/tcpm/anx74xx.c

@@ -1057,6 +1057,8 @@ static int anx74xx_tcpm_init(int port)
 	if (rv)
 		return EC_ERROR_UNKNOWN;
 
+	tcpm_get_chip_info(port, 1, NULL);
+
 	return EC_SUCCESS;
 }