MIPS: panic immediately when panic_on_oops

MIPS wants to sleep 5 seconds before panicking when panic_on_oops is set,
with no apparent reason. Remove this feature, since some users may want
their systems to fail as quickly as possible.

Users who want to delay reboot after panic can use PANIC_TIMEOUT.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12845/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>