jmr3927: do not call tc35815_killall().

No need to stop tc35815 before resetting the board.  This fixes the
build of tc35815 as a module.  This also means there is no caller of
tc35815_killall left, so remove that function also.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>