nvmem: core: fix cleanup after dev_set_name()

In the Linux kernel, the following vulnerability has been resolved: nvmem: core: fix cleanup after dev_set_name() If dev_set_name() fails, we leak nvmem->wp_gpio as the cleanup does not put this. While a minimal fix for this would be to add the gpiod_put() call, we can do better if we split device_register(), and use the tested nvmem_release() cleanup code by initialising the device early, and putting the device. This results in a slightly larger fix, but results in clear code. Note: this patch depends on "nvmem: core: initialise nvmem->id early" and "nvmem: core: remove nvmem_config wp_gpio". [Srini: Fixed subject line and error code handing with wp_gpio while applying.]