memory: tegra: Add API for retrieving carveout bounds

On Tegra234 NVDEC firmware is loaded from a secure carveout, where it
has been loaded by a bootloader. When booting NVDEC, we need to tell it
the address of this firmware, which we can determine by checking the
starting address of the carveout. As such, add an MC API to query the
bounds of carveouts, and add related information on Tegra234.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>