ARM: dts: imx28-cfa10036: Fix the reset gpio signal polarity

The reset signal of the SSD1306 OLED display is actually active-low.
Adapt the DT to reflect the real world.

Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>,
Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>