board: atmel: clean up peripheral clock code

Due to introducing the new peripheral clock handle functions,
use these functions to reduce duplicated code.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Heiko Schocher <hs@denx.de>
[Rebased on current master, fixup for at91rm9200ek]
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/board/atmel/at91sam9rlek/led.c b/board/atmel/at91sam9rlek/led.c
index fede59c..d593aba 100644
--- a/board/atmel/at91sam9rlek/led.c
+++ b/board/atmel/at91sam9rlek/led.c
@@ -8,16 +8,13 @@
 
 #include <common.h>
 #include <asm/arch/at91sam9rl.h>
-#include <asm/arch/at91_pmc.h>
+#include <asm/arch/clk.h>
 #include <asm/arch/gpio.h>
 #include <asm/io.h>
 
 void coloured_LED_init(void)
 {
-	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
-
-	/* Enable clock */
-	writel(ATMEL_ID_PIOD, &pmc->pcer);
+	at91_periph_clk_enable(ATMEL_ID_PIOD);
 
 	at91_set_gpio_output(CONFIG_RED_LED, 1);
 	at91_set_gpio_output(CONFIG_GREEN_LED, 1);