pwm: jz4740: Remove unused devicetree compatible strings

Right now none of the Ingenic-based boards probe this driver from
devicetree. This driver defined three compatible strings for the exact
same behaviour. Before these strings are used, we can remove two of
them.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-jz4740.c

@@ -193,8 +193,6 @@ static int jz4740_pwm_remove(struct platform_device *pdev)
 #ifdef CONFIG_OF
 static const struct of_device_id jz4740_pwm_dt_ids[] = {
 	{ .compatible = "ingenic,jz4740-pwm", },
-	{ .compatible = "ingenic,jz4770-pwm", },
-	{ .compatible = "ingenic,jz4780-pwm", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, jz4740_pwm_dt_ids);