memory: tegra: Consolidate register fields

Subsequent patches will add more register fields to the tegra_mc_client
structure, so consolidate all register field definitions into a common
sub-structure for coherency.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210602163302.120041-2-thierry.reding@gmail.com


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>