MIPS: generic: Return true/false (not 1/0) from bool functions

./arch/mips/generic/board-ocelot.c:29:9-10: WARNING: return of 0/1 in
function 'ocelot_detect' with return type bool

Signed-off-by: Huilong Deng <denghuilong@cdjrlc.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>