coresight: remove the unnecessary configuration coresight-default-sink

The coresight-default-sink configuration option has been
removed from the framework. As such remove it from DT and bindings.

Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 223437c72ae008094e43199dea93c3a144c4e153)
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Conflicts:
	arch/arm/boot/dts/omap3-beagle-xm.dts
	arch/arm/boot/dts/omap3-beagle.dts