spi: fsi: Drop assigning fsi bus

spi: fsi: Drop assigning fsi bus

Since commit FIXME ("fsi: Assign driver's bus in fsi_driver_register()")
module_fsi_driver() cares about assigning the driver's bus member. Drop
the explicit driver specific assignment.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Eddie James <eajames@linux.ibm.com>
Link: https://patch.msgid.link/279e26a6740f10d119be7ea01d4af596309b3bb4.1765279318.git.u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>