gpio: delay: Remove duplicative functionality

Now that GPIO aggregator supports a delay line, drop the duplicative
functionality, i.e. the entire gpio-delay driver.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: andy-shev

drivers/gpio/Kconfig

@@ -1749,15 +1749,6 @@ config GPIO_AGGREGATOR
 	      industrial control context, to be operated from userspace using
 	      the GPIO chardev interface.
 
-config GPIO_DELAY
-	tristate "GPIO delay"
-	depends on OF_GPIO
-	help
-	  Say yes here to enable the GPIO delay, which provides a way to
-	  configure platform specific delays for GPIO ramp-up or ramp-down
-	  delays. This can serve the following purposes:
-	    - Open-drain output using an RC filter
-
 config GPIO_LATCH
 	tristate "GPIO latch driver"
 	help

drivers/gpio/Makefile

@@ -52,7 +52,6 @@ obj-$(CONFIG_GPIO_DA9052)		+= gpio-da9052.o
 obj-$(CONFIG_GPIO_DA9055)		+= gpio-da9055.o
 obj-$(CONFIG_GPIO_DAVINCI)		+= gpio-davinci.o
 obj-$(CONFIG_GPIO_DLN2)			+= gpio-dln2.o
-obj-$(CONFIG_GPIO_DELAY)		+= gpio-delay.o
 obj-$(CONFIG_GPIO_DWAPB)		+= gpio-dwapb.o
 obj-$(CONFIG_GPIO_EIC_SPRD)		+= gpio-eic-sprd.o
 obj-$(CONFIG_GPIO_ELKHARTLAKE)		+= gpio-elkhartlake.o