ARM: dts: exynos: Extend mapped region for DMC on Exynos5422

DMC Adaptive Voltage and Frequency Scaling driver in interrupt mode
needs to access registers at address offset near 0x10000.  These
registers are private DMC performance counters, which might be used
as interrupt trigger when overflow. Potential usage is to skip polling
in devfreq framework and switch to interrupt managed bandwidth control.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>