* boards/arm/tiva/tm4c129e-launchpad: New subdirectory providing
board support for the Texas Instruments TM4C Crypto Connected
LaunchPad, or more correctly the EK-TM4C129EXL.
* Documentation/introduction/detailed_support.rst,
Documentation/introduction/supported_platforms.rst,
boards/README.txt: Document the additional board support.
* boards/Kconfig:
(ARCH_BOARD_TM4C129E_LAUNCHPAD): New config.
(ARCH_BOARD): Add tm4c129e-launchpad.
(Board-Specific Options): Source the board-specific Kconfig
boards/arm/tiva/tm4c129e-launchpad/Kconfig when selected.
