Switch from NVIDIA bootloader tools to tegra-boot-tools

[madisongh]

For Mender builds, replace the tegra-redundant-boot tools from the L4T BSP with tegra-boot-tools:

• Update the Mender state scripts to use the new tools
• For cboot platforms, add bootcount check to initramfs and boot-success marking to normal rootfs using the utilities/services provided by tegra-boot-tools
• Update runtime dependencies where needed to switch to the new tools

After this update:

• The tegra-boot-control utility replaces nvbootctrl. An emulation script for nvbootctrl is added to handle downgrades (since the downloaded state scripts assume nvbootctrl is available).
• The tegra-bootloader-update utility replaces nv_update_engine (and no nv_update_verifier service is installed) on cboot platforms, and replaces l4t_payload_updater_t210 on the TX1/Nano.
• Boot count status can be viewed with tegra-bootinfo --show on cboot platforms.
• The /etc/nv_boot_control.conf file is no longer present, since the new tools don't need it; they instead directly read the information they need from the hardware.
• Bootloader updates on Xavier NX modules/devkits should take about half the time when BUP contents match what's already present in the QSPI flash, since the new tools only write updates when the contents are different.