ARM: dts: s5pv210: Fix camera clock provider on Goni board

The camera driver (according also to bindings) registers a clock
provider if clock-output-names property is present and later the sensors
use registered clocks.

The DTS for S5Pv210 Goni board was incorrectly adding a child node with
clock output cells but without clock-output-names property.  Although
the DTS was compiling (with "/soc/camera/clock-controller: missing or
empty reg/ranges property" warning), the clock provider was not
registered.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>