i2c: thunderx: Add i2c driver for ThunderX SOC

i2c: thunderx: Add i2c driver for ThunderX SOC

BugLink: https://bugs.launchpad.net/bugs/1688132
The ThunderX SOC uses the same i2c block as the Octeon SOC.
The main difference is that on ThunderX the device is a PCI device
so device probing is done via PCI, interrupts are MSI-X. The
clock rates can be set via device tree or ACPI.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
(cherry picked from commit 22d40209de3bb50cbffcc6b79f2f7c5d689d185f)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>