ARM: dts: zynq: Enable PL clocks for Parallella

The Parallella board comes with a U-Boot bootloader that loads one of
two predefined FPGA bitstreams before booting the kernel. Both define an
AXI interface to the on-board Epiphany processor.

Enable clocks FCLK0..FCLK3 for the Programmable Logic by default.

Otherwise accessing, e.g., the ESYSRESET register freezes the board,
as seen with the Epiphany SDK tools e-reset and e-hw-rev, using /dev/mem.

Cc: <stable@vger.kernel.org> # 3.17.x
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Acked-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

arch/arm/boot/dts/zynq-parallella.dts

@@ -34,6 +34,10 @@
 	};
 };
 
+&clkc {
+	fclk-enable = <0xf>;
+};
+
 &gem0 {
 	status = "okay";
 	phy-mode = "rgmii-id";