leds-gpio: of: led should not be created if its status is disabled

now the leds-gpio driver will create every child led node without
checking the status is disabled or not.

for example, if we have a led node like d3, and its status is disabled:
	leds {
		d3 {
			label = "d3";
			gpios = <&pioE 24 0>;
			status = "disabled";
		};
	};

we except the d3 should not be created. And the gpios should not be
request as well.

But current driver will create d3 and request its gpio.

This patch fix this by using for_each_available_child_of_node() to
enumerate all child nodes. So the disabled node will be inavilable.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
sama5d3/dts: move the isi support dt params in a dtsi file

Includes sama5d3mb_isi.dtsi in the end of sama5d3xek.dts will enable ISI
support. Otherwise will enable audio support.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
fb: remove goldfish fb driver

we don't need it anymore

Signed-off-by: Royce Jiang <jiangxd@embedinfo.com>