MIPS: Octeon: Fix build error if CONFIG_MTD=n

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

arch/mips/cavium-octeon/Makefile

@@ -13,10 +13,11 @@ CFLAGS_octeon-platform.o = -I$(src)/../../../scripts/dtc/libfdt
 CFLAGS_setup.o = -I$(src)/../../../scripts/dtc/libfdt
 
 obj-y := cpu.o setup.o serial.o octeon-platform.o octeon-irq.o csrc-octeon.o
-obj-y += dma-octeon.o flash_setup.o
+obj-y += dma-octeon.o
 obj-y += octeon-memcpy.o
 obj-y += executive/
 
+obj-$(CONFIG_MTD)		      += flash_setup.o
 obj-$(CONFIG_SMP)		      += smp.o
 obj-$(CONFIG_OCTEON_ILM)	      += oct_ilm.o