ARM: tegra30: Use cpu* labels

Replace cpu paths with labels since those already exist in tree.

Signed-off-by: Maxim Schwalm <maxim.schwalm@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>