drm/amd/pm/powerplay/smumgr: Fix PCIeBootLinkLevel value on Fiji

drm/amd/pm/powerplay/smumgr: Fix PCIeBootLinkLevel value on Fiji

Previously this was initialized with zero which represented PCIe Gen
1.0 instead of using the
maximum value from the speed table which is the behaviour of all other
smumgr implementations.

Fixes: 18edef19ea44 ("drm/amd/powerplay: implement fw image related smu interface for Fiji.")
Signed-off-by: John Smith <itistotalbotnet@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>