i2c: tegra: add support for fast plus (FM+) mode clock rate

Tegra I2C controller required to configure the clock divisor
register inside controller to different value based on the clock
speed. The recommended clock divisor for the I2C controller for
standard/fast mode is 0x19 and for fast-mode plus is 0x10.

Add support to configure clock divisor register of I2C controller
based on bus clock rate.

This clock divisor is supported form T114 onwards.

Signed-off-by: Chaitanya Bandi <bandik@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --cc drivers/i2c/busses/i2c-tegra.c
Simple merge