atmel, at91: fix smartweb board

since commit: f8b7fff1d5c5 "serial: atmel_usart: Add clk support"

smartweb board comes not up anymore. Fix it.

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Wenyou Yang <wenyou.yang@microchip.com>
diff --git a/configs/smartweb_defconfig b/configs/smartweb_defconfig
index 48c8781..a769fc5 100644
--- a/configs/smartweb_defconfig
+++ b/configs/smartweb_defconfig
@@ -7,6 +7,7 @@
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y
 CONFIG_SPL_LIBGENERIC_SUPPORT=y
+CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_DEFAULT_DEVICE_TREE="at91sam9260-smartweb"
 CONFIG_FIT=y
@@ -33,6 +34,8 @@
 # CONFIG_DOS_PARTITION is not set
 CONFIG_OF_CONTROL=y
 CONFIG_OF_EMBED=y
+CONFIG_CLK=y
+CONFIG_CLK_AT91=y
 CONFIG_DFU_NAND=y
 # CONFIG_MMC is not set
 CONFIG_USB=y