MIPS: cpu/mips/Makefile: Add a missing START line
In the commit 79b51ff8205f0354d5300570614c1d2db499679c ([MIPS] cpu/mips/
Makefile: Split [CS]OBJS onto separate lines), I wrongly deleted a START
line. This patch puts it back.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>