ARM: dts: imx28-m28cu3: Remove 'reset-active-high'

The 'reset-active-high' property is not defined anywhere, so just remove it.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>