/INSTALL_BANANAPI.TXT: Updated.
/INSTALL_KIRKWOOD.TXT: Updated.
/INSTALL_QEMU.TXT: Updated.
In preparation for Slackware AArch64:
The 'boardsupport' directory has been renamed 'platform'.
The sub directory 'u-boot' has been renamed 'bootware'.
Updated asset URLs references accordingly.
You do not need to change anything - these changes affect the documented
installation process only.