Original busy loop with retries count in mpf_poll_status() is not too
reliable, as it takes different times on different systems. Replace it
with read_poll_timeout() macro.

While at it, fix polling stop condition to met function's original
intention declared in the comment. The issue with original polling stop
condition is that it stops if any of mask bits is set, while intention
was to stop if all mask bits is set. This was not noticible because only
MPF_STATUS_READY is passed as mask argument and it is BIT(1).

Fixes: 5f8d4a90 ("fpga: microchip-spi: add Microchip MPF FPGA manager")
Signed-off-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20221230092922.18822-3-i.bornyakov@metrotek.ruSigned-off-by: Xu Yilun <yilun.xu@intel.com>