Add missing PTC memory client latency allowness entry to the Tegra MC
drivers.

This prevents erroneous clearing of MC_INTSTATUS 0x0 register during
of the LA programming in tegra_mc_setup_latency_allowance() due to the
missing entry. Note that this patch doesn't fix any known problems.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20201104164923.21238-32-digetx@gmail.comSigned-off-by: Krzysztof Kozlowski <krzk@kernel.org>