[MIPS] Change libgcc-style functions from lib-y to obj-y

Reported by Eugene Surovegin <ebs@ebshome.net>.

If only modules were users of these functions they did not get linked into
the kernel proper, so later module loads would fail as well.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/lib/Makefile

@@ -9,4 +9,4 @@ obj-y			+= iomap.o
 obj-$(CONFIG_PCI)	+= iomap-pci.o
 
 # libgcc-style stuff needed in the kernel
-lib-y += ashldi3.o ashrdi3.o lshrdi3.o ucmpdi2.o
+obj-y += ashldi3.o ashrdi3.o lshrdi3.o ucmpdi2.o