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/esd/meesc/meesc.c b/board/esd/meesc/meesc.c
index b7f9f90..fe781dc 100644
--- a/board/esd/meesc/meesc.c
+++ b/board/esd/meesc/meesc.c
@@ -87,9 +87,8 @@
 #ifdef CONFIG_MACB
 static void meesc_macb_hw_init(void)
 {
-	at91_pmc_t	*pmc	= (at91_pmc_t *) ATMEL_BASE_PMC;
-	/* Enable clock */
-	writel(1 << ATMEL_ID_EMAC, &pmc->pcer);
+	at91_periph_clk_enable(ATMEL_ID_EMAC);
+
 	at91_macb_hw_init();
 }
 #endif
@@ -244,12 +243,10 @@
 
 int board_early_init_f(void)
 {
-	at91_pmc_t	*pmc	= (at91_pmc_t *) ATMEL_BASE_PMC;
-
-	/* enable all clocks */
-	writel((1 << ATMEL_ID_PIOA) | (1 << ATMEL_ID_PIOB) |
-		(1 << ATMEL_ID_PIOCDE) | (1 << ATMEL_ID_UHP),
-		&pmc->pcer);
+	at91_periph_clk_enable(ATMEL_ID_PIOA);
+	at91_periph_clk_enable(ATMEL_ID_PIOB);
+	at91_periph_clk_enable(ATMEL_ID_PIOCDE);
+	at91_periph_clk_enable(ATMEL_ID_UHP);
 
 	at91_seriald_hw_init();