km/common: move ivm functions from to ivm.c

The file common.c grows in the past. So move the IVM specific
code into an ivm.c file.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Heiko Schocher <hs@denx.de>
cc: Wolfgang Denk <wd@denx.de>
diff --git a/board/keymile/km_arm/Makefile b/board/keymile/km_arm/Makefile
index 6bcfb25..4907030 100644
--- a/board/keymile/km_arm/Makefile
+++ b/board/keymile/km_arm/Makefile
@@ -29,7 +29,7 @@
 
 LIB	= $(obj)lib$(BOARD).o
 
-COBJS	:= $(BOARD).o ../common/common.o
+COBJS	:= $(BOARD).o ../common/common.o ../common/ivm.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))