board: altera: delete unused source files

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Scott McNutt <smcnutt@psyent.com>
2 files changed