spi: amlogic-spifc-a1: Handle devm_pm_runtime_enable() errors

spi: amlogic-spifc-a1: Handle devm_pm_runtime_enable() errors

devm_pm_runtime_enable() can fail due to memory allocation. The current
code ignores its return value, potentially causing runtime PM operations
to fail silently after autosuspend configuration.

Check the return value of devm_pm_runtime_enable() and return on failure.

Fixes: 909fac05b926 ("spi: add support for Amlogic A1 SPI Flash Controller")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Link: https://patch.msgid.link/20251124015852.937-1-vulab@iscas.ac.cn
Signed-off-by: Mark Brown <broonie@kernel.org>