Added checks to avoid potential out of bounds errors which can happen if
the 'slave map' and 'CBB errors' arrays are not correct or latest where
some entries are missing.

Fixes: fc2f151d ("soc/tegra: cbb: Add driver for Tegra234 CBB 2.0")
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>