This patch adds support for the PCI(e) based I2C cores. Which can be
found for example on the Intel Bay Trail SoC. It has 7 I2C controllers
implemented as PCI devices.

This patch also adds the fixed values for the timing registers for
BayTrail which are taken from the Linux designware I2C driver.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>