ARM: dts: s5pv210: replace deprecated "gpios" i2c-gpio property in Aquila

"gpios" property is deprecated.  Update the Aquila DTS to fix
dtbs_checks warnings like:

  i2c-pmic: 'sda-gpios' is a required property
  i2c-pmic: 'scl-gpios' is a required property

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200907161141.31034-23-krzk@kernel.org