CVE-2025-21982 pinctrl: nuvoton: npcm8xx: Add NULL check in npcm8xx_gpio_fw

In the Linux kernel, the following vulnerability has been resolved: pinctrl: nuvoton: npcm8xx: Add NULL check in npcm8xxgpiofw devmkasprintf calls can return null pointers on failure. But the return values were not checked in npcm8xxgpiofw. Add NULL check in npcm8xxgpiofw, to handle kernel NULL...