board/ti/am62x-sk: move post-build.sh to board/ti/common/am6xx

The patch makes it clear that the moved script can be used by the
am6{2,4}x platforms.

Reviewed-by: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Romain Naour <romain.naour@smile.fr>
2 files changed