memory: tegra: Introduce memory client hot reset

In order to reset busy HW properly, memory controller needs to be
involved, otherwise it is possible to get corrupted memory or hang machine
if HW was reset during DMA. Introduce memory client 'hot reset' that will
be used for resetting of busy HW.

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