drm/amd/pm: Fix memory some memory corruption

The "od_table" is a pointer to a large struct, but this code is doing
pointer math as if it were pointing to bytes.  It results in writing
far outside the struct.

Fixes: 2e8452ea ("drm/amd/pm: fulfill the OD support for SMU13.0.0")
Fixes: 2a9aa52e ("drm/amd/pm: fulfill the OD support for SMU13.0.7")
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>