dp: Switch DP thread trigger from semaphore to event #876

Job	Run time
manifest-check	1m 35s
LP64-WIP	1m 35s
build-windows (mtl lnl)	1m 22s
build-windows (imx8 imx8x imx8m imx8ulp)	1m 36s
build-windows (ptl)	1m 45s
build-windows (-d, lnl)	1m 38s
build-linux (mnfst, imx8 imx8x imx8m imx8ulp)	1m 35s
build-windows (tgl tgl-h)	1m 38s
build-linux (mnfst, tgl tgl-h)	1m 36s
build-linux (zmain, mtl lnl)	1m 37s
build-linux (mnfst, ptl)	1m 36s
build-linux (zmain, imx8 imx8x imx8m imx8ulp)	1m 35s
build-linux (zmain, tgl tgl-h)	1m 37s
build-linux (-d, mnfst, lnl)	1m 37s
build-linux (zmain, ptl)	1m 36s
build-linux (mnfst, --all)	1m 16s
build-linux (mnfst, mtl lnl)	1s
compare-linux-win	26s
	25m 41s

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