[master] Missing rm692c9 devicetree file when building for imx8mm-lpddr4-evk machine

[dv1]

I got an error when trying to build the linux-fslc-imx kernel for the imx8mm-lpddr4-evk machine . It turns out that the rm692c9 devicetree file could not be located. The error output is:

| make[3]: *** No rule to make target 'arch/arm64/boot/dts/freescale/imx8mm-evk-rm692c9.dtb'.  Stop.
| make[2]: *** [/build/yocto-bsp-master/build/tmp/work-shared/imx8mm-lpddr4-evk/kernel-source/scripts/Makefile.build:478: arch/arm64/boot/dts/freescale] Error 2
| make[1]: *** [/build/yocto-bsp-master/build/tmp/work-shared/imx8mm-lpddr4-evk/kernel-source/Makefile:1408: freescale/imx8mm-evk-rm692c9.dtb] Error 2
| make: *** [/build/yocto-bsp-master/build/tmp/work-shared/imx8mm-lpddr4-evk/kernel-source/Makefile:224: __sub-make] Error 2

A quick fix was to remove that DTB from the machine config:

diff --git a/conf/machine/imx8mm-lpddr4-evk.conf b/conf/machine/imx8mm-lpddr4-evk.conf
index ae81a92d..e21d8bf8 100644
--- a/conf/machine/imx8mm-lpddr4-evk.conf
+++ b/conf/machine/imx8mm-lpddr4-evk.conf
@@ -20,7 +20,6 @@ KERNEL_DEVICETREE:append:use-nxp-bsp = " \
     freescale/${KERNEL_DEVICETREE_BASENAME}-inmate.dtb \
     freescale/${KERNEL_DEVICETREE_BASENAME}-qca-wifi.dtb \
     freescale/${KERNEL_DEVICETREE_BASENAME}-revb-qca-wifi.dtb \
-    freescale/${KERNEL_DEVICETREE_BASENAME}-rm692c9.dtb \
     freescale/${KERNEL_DEVICETREE_BASENAME}-root.dtb \
     freescale/${KERNEL_DEVICETREE_BASENAME}-rpmsg.dtb \
     freescale/${KERNEL_DEVICETREE_BASENAME}-rpmsg-wm8524.dtb \

IMX_DEFAULT_BSP is set to nxp. meta-freescale git HEAD is at 8ca5ffee50681427b158015335766bf71052763c.