kinox: Allow I2C speed change on port 0 (tcpc0)
kinox: Allow I2C speed change on port 0 (tcpc0)

Add flag for allow i2c speed change.

BUG=b:233298528
BRANCH=none
TEST=Switched I2C bus speed between 400 kHz and 1 MHz. And update the
PDFW success.

Signed-off-by: Matt Wang <0064e31fefe69053c2d155df584f3e8dbe0d4b87@compal.corp-partner.google.com>
Change-Id: I2df4fa1ea4591ae3fe151e9cb37f28a912e9d8b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3659124
Reviewed-by: Zhuohao Lee <916bf7ddbf0565669e59e3cb2b613381a48066c0@chromium.org>
Reviewed-by: Elthan Huang <a5682efe0e7006173fa6b468bbf36cc9c182d5a5@compal.corp-partner.google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec