spidev: avoid warning when used directly in device tree

Avoid warning

    [    2.991522] spidev spi2.2: buggy DT: spidev listed directly in DT

when using spidev in device tree. See

    raspberrypi/linux#1054

Signed-off-by: Stefan Christ <s.christ@phytec.de>
Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Signed-off-by: Jan Remmet <j.remmet@phytec.de>
Signed-off-by: Yunus Bas <y.bas@phytec.de>
Signed-off-by: Andrej Picej <andrej.picej@norik.com>
Reviewed-by: Yunus Bas <y.bas@phytec.de>

drivers/spi/spidev.c

@@ -696,6 +696,8 @@ static const struct of_device_id spidev_dt_ids[] = {
  { .compatible = "menlo,m53cpld" },
  { .compatible = "cisco,spi-petra" },
  { .compatible = "micron,spi-authenta" },
+ /* avoids warning "buggy DT: spidev listed directly in DT" */
+ { .compatible = "spidev" },
  {},
 };
 MODULE_DEVICE_TABLE(of, spidev_dt_ids);