drm/amd/powerplay: correct i2c eeprom init/fini sequence

As data transfer may starts immediately after i2c eeprom init
completed. Thus i2c eeprom should be initialized after SMU
ready. And i2c data transfer should be prohibited when SMU
down. That is the i2c eeprom fini sequence needs to be
updated also.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>