gpio: at91_gpio: remove CPU_HAS_PIO3 macro

The intention of the removal is the preparation to introduce the
new AT91 PIO pinctrl driver.

Use the union to make the PIO3 and PIO2's registers be together
and make their offset aligned.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/atmel/at91sam9n12ek/at91sam9n12ek.c b/board/atmel/at91sam9n12ek/at91sam9n12ek.c
index fc4f50d..58da2d2 100644
--- a/board/atmel/at91sam9n12ek/at91sam9n12ek.c
+++ b/board/atmel/at91sam9n12ek/at91sam9n12ek.c
@@ -71,10 +71,10 @@
 	/* Configure ENABLE pin for NandFlash */
 	at91_set_pio_output(AT91_PIO_PORTD, 4, 1);
 
-	at91_set_a_periph(AT91_PIO_PORTD, 0, 1);    /* NAND OE */
-	at91_set_a_periph(AT91_PIO_PORTD, 1, 1);    /* NAND WE */
-	at91_set_a_periph(AT91_PIO_PORTD, 2, 1);    /* ALE */
-	at91_set_a_periph(AT91_PIO_PORTD, 3, 1);    /* CLE */
+	at91_pio3_set_a_periph(AT91_PIO_PORTD, 0, 1);    /* NAND OE */
+	at91_pio3_set_a_periph(AT91_PIO_PORTD, 1, 1);    /* NAND WE */
+	at91_pio3_set_a_periph(AT91_PIO_PORTD, 2, 1);    /* ALE */
+	at91_pio3_set_a_periph(AT91_PIO_PORTD, 3, 1);    /* CLE */
 }
 #endif
 
@@ -194,7 +194,7 @@
 	       &smc->cs[2].mode);
 
 	/* Configure NCS2 PIN */
-	at91_set_b_periph(AT91_PIO_PORTD, 19, 0);
+	at91_pio3_set_b_periph(AT91_PIO_PORTD, 19, 0);
 }
 #endif