fbdev: ssd1307fb: Remove reset-active-low from the DT binding document

Remove reset-active-low from the devicetree binding document. The actual
implementation has never been there in the driver code and there is no
reason to add it because the gpiod API supports gpio flags, including
GPIO_ACTIVE_LOW, directly trough its own devicetree binding.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Benoît Cousson <bcousson@baylibre.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Documentation/devicetree/bindings/display/ssd1307fb.txt

@@ -8,14 +8,14 @@ Required properties:
          0x3c or 0x3d
   - pwm: Should contain the pwm to use according to the OF device tree PWM
          specification [0]. Only required for the ssd1307.
-  - reset-gpios: Should contain the GPIO used to reset the OLED display
+  - reset-gpios: Should contain the GPIO used to reset the OLED display. See
+                 Documentation/devicetree/bindings/gpio/gpio.txt for details.
   - solomon,height: Height in pixel of the screen driven by the controller
   - solomon,width: Width in pixel of the screen driven by the controller
   - solomon,page-offset: Offset of pages (band of 8 pixels) that the screen is
     mapped to.
 
 Optional properties:
-  - reset-active-low: Is the reset gpio is active on physical low?
   - solomon,segment-no-remap: Display needs normal (non-inverted) data column
                               to segment mapping
   - solomon,com-seq: Display uses sequential COM pin configuration