fsi/sbefifo: Clean up correct FIFO when receiving reset request from SBE

When the SBE requests a reset via the down FIFO, that is also the
FIFO we should go and reset ;)

Fixes: 9f4a8a2d ("fsi/sbefifo: Add driver for the SBE FIFO")
Signed-off-by: Joachim Fenkes <FENKES@de.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200724071518.430515-2-joel@jms.id.au


Signed-off-by: Joel Stanley <joel@jms.id.au>