board/freescale: single T1xxx/2xxx readme.txt

The readme.txt would contain similar content for either processor
family, so this patch consolidates the usage and adds the new
T2080 notes.

Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
2 files changed