amd_gpio_init() uses pci_read_config_dword() that returns PCIBIOS_*
codes. The return code is then returned as is but amd_gpio_init() is
a module init function that should return normal errnos.

Convert PCIBIOS_* returns code using pcibios_err_to_errno() into normal
errno before returning it from amd_gpio_init().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240527132345.13956-1-ilpo.jarvinen@linux.intel.comSigned-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>