i2c: amd-mp2: Unregister callback on adapter add failure

In the Linux kernel, the following vulnerability has been resolved: i2c: amd-mp2: Unregister callback on adapter add failure amd_mp2_register_cb() stores the platform I2C context in the MP2 PCI driver's callback table before the adapter is registered. If i2c_add_adapter() fails, probe returns and devres frees the context, but the PCI driver can still dereference the stale pointer from its IRQ and system-sleep callbacks. Unregister the callback before returning the adapter registration error.