soc: imx8m: Use devm_* to simplify probe failure handling

[ Upstream commit 22b03a4e ]

Use device managed functions to simplify handling of failures during
probe. Remove fail paths which are no longer necessary.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Stable-dep-of: cf7139aa ("soc: imx8m: Unregister cpufreq and soc dev in cleanup path")
Signed-off-by: Sasha Levin <sashal@kernel.org>