zephyr: rtos: userspace_helper.h: add sysuser memory partition #23034

Job	Run time
LP64-WIP	7s
manifest-check	14s
build-windows (-d, mnfst, lnl)	22s
build-windows (mnfst, mtl)	19s
build-windows (mnfst, tgl)	57s
build-linux (mnfst, ptl)	11s
build-windows (mnfst, lnl)	19s
build-windows (mnfst, ptl)	23s
build-linux (mnfst, lnl)	9s
build-linux (mnfst, mtl)	13s
build-windows (mnfst, imx8 imx8x)	24s
build-windows (mnfst, tgl-h)	14s
build-linux (-d, mnfst, lnl)	15s
build-windows (mnfst, imx8m imx8ulp)	57s
build-linux (mnfst, imx8m imx8ulp)	15s
build-linux (mnfst, tgl)	14s
build-linux (mnfst, imx8 imx8x)	14s
build-linux (mnfst, wcl imx95)	9s
build-linux (mnfst, tgl-h)	16s
compare-linux-win	20s
	6m 32s

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