ARM: dts: imx53: Add AHCI SATA DT node

The AHCI-IMX driver now supports i.MX53 as well. Add DT node.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Richard Zhu <r65037@freescale.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Linux-IDE <linux-ide@vger.kernel.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>