fsi: sbefifo: Remove limits on user-specified read timeout

There's no reason to limit the user here. The way the driver is
designed, extremely large transfers require extremely long timeouts.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20230612195657.245125-7-eajames@linux.ibm.com


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