dt-bindings: power: supply: bq24735: reverse the polarity of ac-detect

The ACOK pin on the bq24735 is active-high, of course meaning that when
AC is OK the pin is high. However, all Tegra dts files have incorrectly
specified active-high even though the signal is inverted on the Tegra
boards. This has worked since the Linux driver has also inverted the
meaning of the GPIO. Fix this situation by simply specifying in the
bindings what everybody else agrees on; that the ti,ac-detect-gpios is
active on AC adapter absence.

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

Documentation/devicetree/bindings/power/supply/ti,bq24735.txt

@@ -8,8 +8,10 @@ Optional properties :
  - interrupts : Specify the interrupt to be used to trigger when the AC
    adapter is either plugged in or removed.
  - ti,ac-detect-gpios : This GPIO is optionally used to read the AC adapter
-   presence. This is a Host GPIO that is configured as an input and
-   connected to the bq24735.
+   status. This is a Host GPIO that is configured as an input and connected
+   to the ACOK pin on the bq24735. Note: for backwards compatibility reasons,
+   the GPIO must be active on AC adapter absence despite ACOK being active
+   (high) on AC adapter presence.
  - ti,charge-current : Used to control and set the charging current. This value
    must be between 128mA and 8.128A with a 64mA step resolution. The POR value
    is 0x0000h. This number is in mA (e.g. 8192), see spec for more information