drivers: i2c: rename twihs_sam to i2c_sam_twihs

Rename the Atmel SAM I2C driver based on TWIHS module to match the
convention:
<driver class>_<SoC family>_<hardware module used by the driver>

Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>
4 files changed