m68k: add dspi chip-select support

Signed-off-by: Angelo Dureghello <angelo@sysam.it>

Changes for v5:
- new patch
diff --git a/arch/m68k/cpu/mcf5227x/Makefile b/arch/m68k/cpu/mcf5227x/Makefile
index ef43893..6a38c48 100644
--- a/arch/m68k/cpu/mcf5227x/Makefile
+++ b/arch/m68k/cpu/mcf5227x/Makefile
@@ -6,4 +6,4 @@
 # ccflags-y += -DET_DEBUG
 
 extra-y	= start.o
-obj-y	= cpu.o speed.o cpu_init.o interrupts.o
+obj-y	= cpu.o speed.o cpu_init.o interrupts.o dspi.o