board/samsung/universal_c210/universal.c: Fix build warning

Fix:
universal.c: In function 's5pc210_phy_control':
universal.c:273:7: warning: 'ret' may be used uninitialized
in this function [-Wuninitialized]

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Acked-by: Minkyu Kang <mk7.kang@samsung.com>

board/samsung/universal_c210/universal.c

@@ -260,7 +260,7 @@ int board_mmc_init(bd_t *bis)
 #ifdef CONFIG_USB_GADGET
 static int s5pc210_phy_control(int on)
 {
-	int ret;
+	int ret = 0;
 	struct pmic *p = get_pmic();
 
 	if (pmic_probe(p))