ARM: dts: Allow simultaneous usage exynos-rng and s5p-sss drivers on exynos5

ARM: dts: Allow simultaneous usage exynos-rng and s5p-sss drivers on exynos5

The s5p-sss crypto HW acceleration driver supports only AES algorithms
thus it accesses only registers from feeder (offset 0x0, length 0x100)
and AES (offset 0x200, length 0x100) blocks of Security SubSystem (SSS).

The exynos-rng Pseudo Random Number Generator driver accesses only PRNG
block at offset 0x400 (length 0x100).

Narrow the size of memory mapped by s5p-sss driver so both drivers can
be loaded at the same time.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>