ARM926EJ-S: relocate OMAP specific 'cpuinfo.c' into OMAP directory

OMAP identification is implemented in 'cpuinfo.c' and located in ARM926EJ-S directory.
It makes sense to place this file in OMAP specific subdirectory, i.e. cpu/arm926ejs/omap

Signed-off-by: Roman Mashak <romez777@gmail.com>
diff --git a/cpu/arm926ejs/omap/Makefile b/cpu/arm926ejs/omap/Makefile
index c335d5c..74aea74 100644
--- a/cpu/arm926ejs/omap/Makefile
+++ b/cpu/arm926ejs/omap/Makefile
@@ -25,7 +25,7 @@
 
 LIB	= $(obj)lib$(SOC).a
 
-COBJS	= timer.o
+COBJS	= timer.o cpuinfo.o
 SOBJS	= reset.o
 
 SRCS	:= $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)