fsi: sbefifo: Add detailed debugging information

Provide more output on the timeout status, and make some vdbg calls into
dbg calls so they can be enabled at runtime.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220415050757.281158-1-joel@jms.id.au


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