Blackfin: bf533-stamp: split and cleanup CF/IDE code

Give the CF/IDE code its own file to keep things cleanly separated.  While
we're here, clean up the code to use common functions.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/board/bf533-stamp/Makefile b/board/bf533-stamp/Makefile
index dbba12b..832037b 100644
--- a/board/bf533-stamp/Makefile
+++ b/board/bf533-stamp/Makefile
@@ -30,6 +30,7 @@
 LIB	= $(obj)lib$(BOARD).a
 
 COBJS-y	:= $(BOARD).o
+COBJS-$(CONFIG_STAMP_CF) += ide-cf.o
 COBJS-$(CONFIG_VIDEO) += video.o
 
 SRCS	:= $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)