drivers: i2c: thunderx: Allow driver to work with ACPI defined TWSI controllers

Due to i2c->adap.dev.fwnode not being set, ACPI_COMPANION() wasn't properly
found for TWSI controllers.

Signed-off-by: Szymon Balcerak <sbalcerak@marvell.com>
Signed-off-by: Piyush Malgujar <pmalgujar@marvell.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>