powerpc: Stop using of_root #132

Job	Run time
kernel (ppc64_defconfig, fedora-38)	4m 14s
kernel (ppc64_defconfig, korg-5.5.0)	3m 30s
kernel (ppc40x_defconfig, fedora-38)	6m 55s
kernel (ppc40x_defconfig, korg-5.5.0)	4m 26s
kernel (mpc885_ads_defconfig, fedora-38)	7m 14s
kernel (mpc885_ads_defconfig, korg-5.5.0)	4m 47s
kernel (ppc64le_guest_defconfig, fedora-38, ppc64le)	1m 54s
kernel (ppc64le_guest_defconfig, korg-5.5.0, ppc64le)	2m 52s
kernel (ppc44x_defconfig, fedora-38, /linux/arch/powerpc/configs/ppc44x-qemu.config)	7m 16s
kernel (ppc44x_defconfig, korg-5.5.0, /linux/arch/powerpc/configs/ppc44x-qemu.config)	4m 58s
kernel (corenet64_smp_defconfig, fedora-38)	9m 57s
kernel (corenet64_smp_defconfig, korg-5.5.0)	9m 55s
kernel (g5_defconfig, fedora-38, /linux/arch/powerpc/configs/g5-qemu.config)	9m 23s
kernel (g5_defconfig, korg-5.5.0, /linux/arch/powerpc/configs/g5-qemu.config)	9m 21s
kernel (pmac32_defconfig, fedora-38, /linux/arch/powerpc/configs/pmac32-qemu.config)	8m 36s
kernel (pmac32_defconfig, korg-5.5.0, /linux/arch/powerpc/configs/pmac32-qemu.config)	8m 6s
kernel (corenet32_smp_defconfig, fedora-38)	9m 59s
boot	0s
	1h 53m 23s

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