drivers/spi: fsl_qspi: improve timeout calculation

Use readl_poll_timeout instead of explicit calculation

Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
1 file changed