mtd: rawnand: renesas: Handle devm_pm_runtime_enable() errors

mtd: rawnand: renesas: Handle devm_pm_runtime_enable() errors

devm_pm_runtime_enable() can fail due to memory allocation failures.
The current code ignores its return value and proceeds with
pm_runtime_resume_and_get(), which may operate on incorrectly
initialized runtime PM state.

Check the return value of devm_pm_runtime_enable() and return the
error code if it fails.

Fixes: 6a2277a0ebe7 ("mtd: rawnand: renesas: Use runtime PM instead of the raw clock API")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>