On BMCs with lower timer resolution than 1ms, msleep(1) will take
way longer than 1ms, so looping 10k times won't wait for 10s but
significantly longer.

Fix this by using jiffies like the rest of the code.

Fixes: 9f4a8a2d ("fsi/sbefifo: Add driver for the SBE FIFO")
Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Link: https://lore.kernel.org/r/20200724071518.430515-3-joel@jms.id.auSigned-off-by: Joel Stanley <joel@jms.id.au>