gpio: Change ISA_BUS_API dependency to selection

The ISA_BUS_API Kconfig option enables the compilation of the ISA bus
driver. The ISA bus driver does not perform any hardware interaction,
and is instead just a thin layer of software abstraction to eliminate
boilerplate code common to ISA-style device drivers. Since ISA_BUS_API
has no dependencies and does not jeopardize the integrity of the system
when enabled, drivers should select it when the ISA bus driver
functionality is needed.

Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -608,7 +608,8 @@ menu "Port-mapped I/O GPIO drivers"
 
 config GPIO_104_DIO_48E
 	tristate "ACCES 104-DIO-48E GPIO support"
-	depends on PC104 && ISA_BUS_API
+	depends on PC104
+	select ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the ACCES 104-DIO-48E series (104-DIO-48E,
@@ -618,7 +619,8 @@ config GPIO_104_DIO_48E
 
 config GPIO_104_IDIO_16
 	tristate "ACCES 104-IDIO-16 GPIO support"
-	depends on PC104 && ISA_BUS_API
+	depends on PC104
+	select ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the ACCES 104-IDIO-16 family (104-IDIO-16,
@@ -629,7 +631,8 @@ config GPIO_104_IDIO_16
 
 config GPIO_104_IDI_48
 	tristate "ACCES 104-IDI-48 GPIO support"
-	depends on PC104 && ISA_BUS_API
+	depends on PC104
+	select ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the ACCES 104-IDI-48 family (104-IDI-48A,
@@ -649,7 +652,8 @@ config GPIO_F7188X
 
 config GPIO_GPIO_MM
 	tristate "Diamond Systems GPIO-MM GPIO support"
-	depends on PC104 && ISA_BUS_API
+	depends on PC104
+	select ISA_BUS_API
 	help
 	  Enables GPIO support for the Diamond Systems GPIO-MM and GPIO-MM-12.
 
@@ -734,7 +738,7 @@ config GPIO_WINBOND
 
 config GPIO_WS16C48
 	tristate "WinSystems WS16C48 GPIO support"
-	depends on ISA_BUS_API
+	select ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the WinSystems WS16C48. The base port