Blackfin arch: unify the duplicated _real_start functions

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/arch/blackfin/mach-common/Makefile b/arch/blackfin/mach-common/Makefile
index 5e6b20e..862cd73 100644
--- a/arch/blackfin/mach-common/Makefile
+++ b/arch/blackfin/mach-common/Makefile
@@ -3,7 +3,7 @@
 #
 
 obj-y := \
-	cache.o entry.o \
+	cache.o entry.o head.o \
 	interrupt.o lock.o irqpanic.o arch_checks.o ints-priority.o
 
 obj-$(CONFIG_PM)          += pm.o dpmc_modes.o