tests/pflash-cfi02: Add test for supported CFI commands

tests/pflash-cfi02: Add test for supported CFI commands

Test the AMD command set for parallel flash chips. This test uses an
ARM musicpal board with a pflash drive to test the following list of
currently-supported commands.
- Autoselect
- CFI
- Sector erase
- Chip erase
- Program
- Unlock bypass
- Reset

Signed-off-by: Stephen Checkoway <stephen.checkoway@oberlin.edu>
Message-Id: <20190426162624.55977-2-stephen.checkoway@oberlin.edu>
Acked-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[PMD: reworded the patch subject, g_assert_cmpint -> cmphex]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>