ARM: dts: exynos: correct fuel gauge interrupt trigger level on P4 Note family

The Maxim fuel gauge datasheets describe the interrupt line as active
low with a requirement of acknowledge from the CPU.  The falling edge
interrupt will mostly work but it's not correct.

Fixes: f48b5050 ("ARM: dts: exynos: add Samsung's Exynos4412-based P4 Note boards")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201210212534.216197-2-krzk@kernel.org