MIPS: rb532: move GPIOD definition into C-files

My kernel robot reports build error from drivers/iio/adc/da9150-gpadc.c,

drivers/iio/adc/da9150-gpadc.c:254:13: error: ‘DA9150_GPADC_CHAN_0x08’
undeclared here (not in a function); did you mean ‘DA9150_GPADC_CHAN_TBAT’?
254 | .channel = DA9150_GPADC_CHAN_##_id,

We define GPIOD in rb.h, in fact it should only be used in gpio.c, but
it affects the driver da9150-gpadc.c which goes against the original
intention of the design, just move it to its scope.

Fixes: 1b432840d0a4 ("MIPS: RB532: GPIO register offsets are relative to GPIOBASE")
Suggested-by: Jonathan Cameron <[e-mail]>
Suggested-by: Andy Shevchenko <[e-mail]>
Reported-by: k2ci <[e-mail]>
Signed-off-by: Jackie Liu <[e-mail]>
Signed-off-by: Thomas Bogendoerfer <[e-mail]>

arch/mips/include/asm/mach-rc32434/rb.h

···
 #define DEV3TC		0x01003C
 #define BTCS		0x010040
 #define BTCOMPARE	0x010044
-#define GPIOBASE	0x050000
-/* Offsets relative to GPIOBASE */
-#define GPIOFUNC	0x00
-#define GPIOCFG		0x04
-#define GPIOD		0x08
-#define GPIOILEVEL	0x0C
-#define GPIOISTAT	0x10
-#define GPIONMIEN	0x14
-#define IMASK6		0x38
 #define LO_WPX		(1 << 0)
 #define LO_ALE		(1 << 1)
 #define LO_CLE		(1 << 2)

arch/mips/rb532/gpio.c

···
 #include <asm/mach-rc32434/rb.h>
 #include <asm/mach-rc32434/gpio.h>
 
+#define GPIOBASE	0x050000
+/* Offsets relative to GPIOBASE */
+#define GPIOFUNC	0x00
+#define GPIOCFG		0x04
+#define GPIOD		0x08
+#define GPIOILEVEL	0x0C
+#define GPIOISTAT	0x10
+#define GPIONMIEN	0x14
+#define IMASK6		0x38
+
 struct rb532_gpio_chip {
 	struct gpio_chip chip;
 	void __iomem	 *regbase;