install-scripts: Add support of GPT partition type

This is a solution for objective defined in [YT-98] Add GPT support for fng-install.

In this MR, added a new parameter to choose between partition table type: Master Boot Record or GUID Partition Table.
The default partition table type remains MBR for SECO i.MX6/8 boards, and GPT can be activated by passing a --partition-table-type=gpt parameter to fngsystem-self-init.sh script.

How to switch to GPT and install Yocto on top

Notes:
× all commands below are executed in FNG-System on i.MX6 device.
× ⚠ A modern version of sfdisk (at least v2.26) is required. If FNG-System prior to v17.0 is used, upgrade it before switching to GPT: execute fngsystem-self-init.sh without --partition-table-type parameter and reboot.

• Update FNG-Boot to the version with GPT support:

  export TFTP=192.168.0.16/seco-mx6/FNGBoot-v16.0r3966/
  curl tftp://$TFTP/fng_boot_update.sh > fng_boot_update.sh
  chmod +x fng_boot_update.sh
  ./fng_boot_update.sh

• Switch to GPT schema by installing FNG-System. Specify the new partitioning table type as an argument of the script:

  export TFTP=192.168.0.16/seco-mx6/FNGSystem-dev/
  curl tftp://$TFTP/fngsystem-self-init.sh > fngsystem-self-init.sh
  chmod +x fngsystem-self-init.sh
  ./fngsystem-self-init.sh --partition-table-type=gpt

• Install Yocto to GPT partitions via fng-install.sh:

  export TFTP=192.168.0.16/seco-mx6/Yocto-kirkstone/
  curl tftp://$TFTP/fng-install.sh > fng-install.sh
  chmod +x ./fng-install.sh
  ./fng-install.sh

How to switch back to MBR and install an old BSP

Notes:
× all commands below are executed in the latest FNG-System on i.MX6 device.

• Reinstall FNG-System by executing fngsystem-self-init.sh script and specifying the MBR partition table type as a parameter.

  export TFTP=192.168.0.16/seco-mx6/FNGSystem-dev/
  curl tftp://$TFTP/fngsystem-self-init.sh > fngsystem-self-init.sh
  chmod +x fngsystem-self-init.sh
  ./fngsystem-self-init.sh --partition-table-type=mbr

• Reinstall Yocto to MBR via fng-install.sh. (Note: Rocko BSP will be installed):

  export TFTP=192.168.0.16/seco-mx6/Yocto-rocko-12.5-0/
  curl tftp://$TFTP/GUF-Yocto-rocko-12.5-0-IMX6GUF-fng-install.sh > fng-install.sh
  chmod +x ./fng-install.sh
  ./fng-install.sh

Notes and known limitations:

• Testing was performed on i.MX6 (SANTVEND core v1.3) and i.MX8 (Tanaro) boards.