MIPS: Markeins: Remove runtime debug prints

Remove runtime db_* macros as we don't need them any more.  In general,
such helpers are useful for initial porting, but once approved, they are
not indispensable.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>