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: 99bb2032 ("ARM: dts: s5pv210: Correct fuelgauge definition on Aries")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201210212534.216197-10-krzk@kernel.org