This reverts commit e383b127.

Controling hubp power gating using the DMCUB isn't stable so we
are reverting this change to move control back into the driver.

Cc: stable@vger.kernel.org # 6.3+
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Daniel Miess <daniel.miess@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>