test: Add firmware and flash images for use with QEmu

- firmware-TK1-24.03.bin built from tillitis-key1 tag TK1-24.04 (commit
1c90b1aa3dbfb4e62039683ee6049ae8af608498) with:

  make -C contrib run
  cd hw/application_fpga
  make firmware.bin

- qemu_firmware-260225-main-2ffd46c.elf and
flash_image-260225-main-2ffd46c.bin built from tillitis-key1 commit
2ffd46cd31d2d27d69db938535ff970805ddbe5c with:

  make -C contrib run
  cd hw/application_fpga
  make qemu_firmware.elf flash_image.bin

Author: agren