gpu: host1x: Rename relocarray -> relocs for consistency

All other array variables use a plural, and this is the only one using
the *array suffix. This is confusing, so rename it for consistency.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>