board: atmel: Use the new PIT timer driver

Use the Atmel PIT timer driver which supports the driver model
and device tree.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
diff --git a/configs/at91sam9261ek_dataflash_cs3_defconfig b/configs/at91sam9261ek_dataflash_cs3_defconfig
index be221a6..e84c139 100644
--- a/configs/at91sam9261ek_dataflash_cs3_defconfig
+++ b/configs/at91sam9261ek_dataflash_cs3_defconfig
@@ -48,6 +48,8 @@
 CONFIG_ATMEL_USART=y
 CONFIG_DM_SPI=y
 CONFIG_ATMEL_SPI=y
+CONFIG_TIMER=y
+CONFIG_ATMEL_PIT_TIMER=y
 CONFIG_USB=y
 CONFIG_USB_STORAGE=y
 CONFIG_LCD=y