uboot-phytec

MLK-24185: dts: imx8qxp: include the u-boot dtsi in gpmi dts

include the fsl-imx8qxp-lpddr4-val-u-boot.dtsi explicitly in
imx8qxp-lpddr4-val-gpmi-nand.dts, otherwise boot image failed to boot
due to some power domains were not enabled.

Signed-off-by: Han Xu <han.xu@nxp.com>
(cherry picked from commit 06ddd9e78bcad974fc4f0f05c6dcfacf8551d2d5)