regulator: da9121: Remove unused of_gpio.h

of_gpio.h is deprecated and subject to remove.
The driver doesn't use it, simply remove the unused header.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240228195730.3607154-1-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/da9121-regulator.c

@@ -14,7 +14,6 @@
 // Copyright (C) 2020 Dialog Semiconductor
 
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/machine.h>