[DO NOT MERGE THIS YET] remove rimage submodule #754

Job	Run time
LP64-WIP	59s
build-linux (mnfst, imx8 imx8x imx8m)	51s
build-linux (mnfst, mtl)	48s
build-windows (imx8 imx8x imx8m)	7m 5s
manifest-check	1m 9s
build-linux (mnfst, lnl)	46s
build-windows (mtl)	5m 39s
build-linux (mnfst, tgl tgl-h)	57s
build-windows (tgl tgl-h)	6m 8s
build-linux (zmain, imx8 imx8x imx8m)	56s
build-windows (-d, mtl)	7m 53s
build-linux (zmain, mtl)	48s
build-linux (zmain, lnl)	46s
build-linux (zmain, tgl tgl-h)	46s
build-linux (-d, mnfst, mtl)	46s
compare-linux-win	18s
	36m 35s

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