tests/boot_linux_console: Tag Emcraft Smartfusion2 as running 'u-boot'

tests/boot_linux_console: Tag Emcraft Smartfusion2 as running 'u-boot'

Avocado tags are handy to automatically select tests matching
the tags. Since this test also runs U-Boot, tag it.

We can run all the tests using U-Boot as once with:

  $ avocado --show=app run -t u-boot tests/acceptance/
  JOB LOG    : avocado/job-results/job-2020-01-21T00.16-ee9344e/job.log
   (1/3) tests/acceptance/boot_linux_console.py:BootLinuxConsole.test_arm_emcraft_sf2: PASS (16.59 s)
   (2/3) tests/acceptance/boot_linux_console.py:BootLinuxConsole.test_arm_raspi2_uboot: PASS (0.47 s)
   (3/3) tests/acceptance/boot_linux_console.py:BootLinuxConsole.test_aarch64_raspi3_uboot: PASS (2.43 s)
  RESULTS    : PASS 3 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
  JOB TIME   : 19.78 s

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-Id: <20200120235159.18510-8-f4bug@amsat.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>