ARM: mx28: set proper parent for lcdif clock

Most likely, the LCD panel on mx28 platform will require a pixel
clock higher than ref_xtal_clk (24 MHz), so the patch initializes
the parent of lcdif clock as ref_pix_clk.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mxs/clock-mx28.c

@@ -750,6 +750,8 @@ int __init mx28_clocks_init(void)
 	clk_enable(&emi_clk);
 	clk_enable(&uart_clk);
 
+	clk_set_parent(&lcdif_clk, &ref_pix_clk);
+
 	clkdev_add_table(lookups, ARRAY_SIZE(lookups));
 
 	mxs_timer_init(&clk32k_clk, MX28_INT_TIMER0);