imx: mx6: correct enable_fec_anatop_clock

We should follow 'read->set/clr bit->write' flow for enable_fec_anatop_clock,
otherwise we may overridden configuration before enable_fec_anatop_clock.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Cc: Fabio Estevam <fabio.estevam@freescale.com>

arch/arm/cpu/armv7/mx6/clock.c

@@ -535,6 +535,8 @@ int enable_fec_anatop_clock(int fec_id, enum enet_freq freq)
 	if (freq < ENET_25MHZ || freq > ENET_125MHZ)
 		return -EINVAL;
 
+	reg = readl(&anatop->pll_enet);
+
 	if (fec_id == 0) {
 		reg &= ~BM_ANADIG_PLL_ENET_DIV_SELECT;
 		reg |= BF_ANADIG_PLL_ENET_DIV_SELECT(freq);