ARM: dts: s5pv210: Enable ADC on Aries boards

On Aries boards, the ADC is used for things such as jack detection
and battery temperature monitoring.  It is supplied by LDO4 of max8998,
so only enable that regulator when we are actually using the ADC.

Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>