linux-wandboard

MLK-15076: arm: dts: insulate ULP kernel boot from M4 boot

i.MX7ULP QSPI dtb was used to update the M4 images, it should not able
to boot the kernel even without the M4 image in QSPI.

Also fixed the typo in dtsi to correct the QSPI register address
mapping range.

Signed-off-by: Han Xu <han.xu@nxp.com>