drm/amd/powerplay: fix memory leak of tdp_table

tdp_table is being leaked on failed allocations of
hwmgr->dyn_state.cac_dtp_table. kfree tdp_table on the error
return path to fix the leak.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>