Log Message:
libretro-freeintv: Update to 20200421

Changes:
     * Fixes graphics issues – Intellivania not working on emulator
     * Correctly detect MTE Test Cart
     * Fixes #40 – Intellicart roms w/o A8 –
       Detects Intellicart roms using a different method for files that don’t
       begin with 0xA8
     * Expose RAM for Retroachievements
     * OSD, Keyboard keypad controls –
       keys 0-9 as expected. [ and ] replace C and E
       OSD updated, real messages replace cryptic “colored pixel” loading
       error feedback