soc/tegra: fuse: Fix index bug in get_process_id

This patch simply fixes a bug of referencing speedos[num] in every
for-loop iteration in get_process_id function.

Fixes: 0dc5a0d8 ("soc/tegra: fuse: Add Tegra210 support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>