linux-phytec-ti

sh: mach-systemh: Kill off dead board.

This code has been untouched since it was merged many years ago, and has
severely bitrotted since, suggesting that the board has no real users
left. Notice of intent to remove has been sent out over the last few
years, with no takers. Kill it off.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>