drm/amd: Fix amdgpu_device_find_parent()

drm/amd: Fix amdgpu_device_find_parent()

commit eb53125a7ad9 ("drm/amd: Add dedicated helper for
amdgpu_device_find_parent()") created a dedicated helper to find
the parent device outside of the dGPU but it had a logic error
that caused it to walk all the way up the topology and return
the wrong device.

Break out of the loop when the device is found.

Reviewed-by: Alexander Deucher <alexander.deucher@amd.com>
Fixes: eb53125a7ad9 ("drm/amd: Add dedicated helper for amdgpu_device_find_parent()")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>