dp: Switch DP thread trigger from semaphore to event #878

Job	Run time
LP64-WIP	4m 35s
manifest-check	3m 7s
build-windows (tgl tgl-h)	11m 55s
build-windows (ptl)	9m 27s
build-windows (-d, lnl)	9m 8s
build-windows (mtl lnl)	12m 19s
build-linux (mnfst, mtl lnl)	5m 35s
build-windows (imx8 imx8x imx8m imx8ulp)	13m 35s
build-linux (zmain, imx8 imx8x imx8m imx8ulp)	4m 5s
build-linux (zmain, mtl lnl)	3m 44s
build-linux (zmain, ptl)	3m 24s
build-linux (mnfst, imx8 imx8x imx8m imx8ulp)	7m 12s
build-linux (zmain, tgl tgl-h)	3m 56s
build-linux (mnfst, tgl tgl-h)	6m 32s
build-linux (mnfst, --all)	12m 46s
build-linux (mnfst, ptl)	6m 27s
build-linux (-d, mnfst, lnl)	4m 37s
compare-linux-win	53s
	2h 3m 17s

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