ARM: dts: exynos: MCT is not an interrupt controller and extend length of iomap

Multi-Core Timer generates interrupts but it is not really an interrupt
controller so remove the "interrupt-controller" and "interrupt-cells"
properties. Additionally extend the length of mapped memory to cover all
registers (last SFR is at 0x0A40).

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>