ARM: dts: imx6dl-victgo.dts: update gpio names

Following changes was made:
- Add MDIO signal names
- Add missing ISB_IN2 name. Also correct ISB_nIN1. These two signals were used
  together in older HW revisions. Later ISB_IN2 was removed. Software should
  still be able to use both.
- Add missing CAN1 and UART line names
- Add missing ON1/2_CTRL line names
- fix CPU_* line names. The real signal names are without the CPU_ prefix, like
  on imx6qdl-vicut1.dtsi
- Fix ETH_INT signal name

Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>