drm/amdgpu: fix an amdgpu_irq_put() issue in gmc_v9_0_hw_fini()

As made mention of in commit c56edea5 ("drm/amdgpu: fix
amdgpu_irq_put call trace in gmc_v10_0_hw_fini") and commit aa6ac247
("drm/amdgpu: fix amdgpu_irq_put call trace in gmc_v11_0_hw_fini"). It
is meaningless to call amdgpu_irq_put() for gmc.ecc_irq. So, remove it
from gmc_v9_0_hw_fini().

Link: drm/amd#2522


Fixes: c8b5a95b ("drm/amdgpu: Fix desktop freezed after gpu-reset")
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>