ARM: dts: imx6q: Add ENET PTP clock pin and clock source

Add ENET 1588 clock input pin
MX6Q_PAD_GPIO_16__ENET_ANATOP_ETHERNET_REF_OUT
and anatop PLL8 clock source for ENET

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>