ARM: dts: imx7-colibri: clean-up usdhc1 and add sleep config

ARM: dts: imx7-colibri: clean-up usdhc1 and add sleep config

Adding no-1-8-v property to usdhc1 to disable +1.8V signaling (UHS-I)
mode on SoM dtsi level.

Clean up no-1-8-v from Aster carrier board dtsi, which is using defaults
from SoM dtsi and is not UHS-I capable.

A carrier board may have a MMC/SD card slot with a switchable power
supply. Add a pinctrl sleep used when the card power is off to avoid
backfeeding to the card and add the "sleep" pinctrl to the usdhc1
controller.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>