ARM: dts: imx6q-sabrelite: add ecspi1 pinctrl support

Imx6q sabrelite board uses ecspi1 to connect a spi flash sst25vf016b,
we need to add pinctrl information for it in the dts, otherwise the
ecspi1 driver can't work and the connected flash is wrongly
detected as a mr25h256 flash like this:

m25p80 spi32766.0: found mr25h256, expected sst25vf016b
m25p80 spi32766.0: mr25h256 (32 Kbytes)

Cc: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Hui Wang <jason77.wang@gmail.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>