ARM: dts: exynos: Disable ARM PMU on Odroid XU3-lite

ARM Performance Monitoring Units (PMUs) are permanently disabled in the
Exynos5422 SoC version used on Odroid XU3-lite boards. Disable them in
boards dtb to avoid confusing user and getting following warning on boot:

hw-breakpoint: Failed to enable monitor mode on CPU 0

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>