remoteproc: imx_rproc: Use devm_clk_get_enabled() and simplify cleanup

remoteproc: imx_rproc: Use devm_clk_get_enabled() and simplify cleanup

Replace separate calls to devm_clk_get() and clk_prepare_enable() with
devm_clk_get_enabled(), which combines clock acquisition and enabling
into a single managed step. Simplify the probe logic and remove the need
for manual clock disable in error and remove paths.

Also, update error handling to eliminate redundant cleanup steps and use
return-based error propagation where appropriate. Improve code clarity and
reduce the chance of resource leaks or incorrect ordering in cleanup paths.

No functional changes.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20250926-imx_rproc_v3-v3-4-4c0ec279cc5f@nxp.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>