ARM: dts: exynos: Use labels instead of full paths in exynos4210

Extend camera, mixer and tmu nodes by labels, not by full path in Exynos
4210 DTSI.  This avoids error-prone redefinition of nodes.

Signed-off-by: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>