ARM: dts: da850-lego-ev3: Fix battery voltage gpio

This fixes the battery voltage monitoring gpio-hog settings.

When the gpio is low, it turns off the battery voltage to the ADC chip.
However, this needs to be on all of the time so that we can monitor
battery voltage.

Also, there was a typo that prevented pinmuxing from working correctly.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>