ARM: dts: imx6qdl-sabrelite: move spi-nor CS to pinctrl_ecspi1

This patch moves pin EIM_D19 (CS) from pinctrl_hog to pinctrl_ecspi1.
It also explicitly sets the pad to 0x000b1.

Before this patch, it has the value 0x100b1 if using mainline u-boot.
So this patch also removes hysteresis since the pad is always an output.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>