ARM: configs: at91: sama5: PIOBU as built-in

Include as built-in as it's used by multiple boards.
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
[nicolas.ferre@microchip.com: adap to newer kernel]
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>

arch/arm/configs/sama5_defconfig

@@ -123,7 +123,7 @@ CONFIG_SPI_ATMEL=y
 CONFIG_SPI_ATMEL_QUADSPI=y
 CONFIG_SPI_GPIO=y
 CONFIG_GPIO_SYSFS=y
-CONFIG_GPIO_SAMA5D2_PIOBU=m
+CONFIG_GPIO_SAMA5D2_PIOBU=y
 CONFIG_POWER_RESET=y
 CONFIG_POWER_SUPPLY=y
 CONFIG_BATTERY_ACT8945A=y