Refactor OneNAND IPL code

Refactoring the OneNAND IPL code

and some minor fixed:
- Remove unnecessary header file
- Fix wrong access at read interrupt
- The recent OneNAND has 4KiB pagesize

Also Board can override OneNAND IPL image

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/Makefile b/Makefile
index 9c5b2a5..30a35f3 100644
--- a/Makefile
+++ b/Makefile
@@ -285,6 +285,7 @@
 ifeq ($(CONFIG_ONENAND_U_BOOT),y)
 ONENAND_IPL = onenand_ipl
 U_BOOT_ONENAND = $(obj)u-boot-onenand.bin
+ONENAND_BIN ?= $(obj)onenand_ipl/onenand-ipl-2k.bin
 endif
 
 __OBJS := $(subst $(obj),,$(OBJS))
@@ -378,8 +379,7 @@
 		$(MAKE) -C onenand_ipl/board/$(BOARDDIR) all
 
 $(U_BOOT_ONENAND):	$(ONENAND_IPL) $(obj)u-boot.bin
-		cat $(obj)onenand_ipl/onenand-ipl-2k.bin $(obj)u-boot.bin > $(obj)u-boot-onenand.bin
-		cat $(obj)onenand_ipl/onenand-ipl-4k.bin $(obj)u-boot.bin > $(obj)u-boot-flexonenand.bin
+		cat $(ONENAND_BIN) $(obj)u-boot.bin > $(obj)u-boot-onenand.bin
 
 $(VERSION_FILE):
 		@( printf '#define U_BOOT_VERSION "U-Boot %s%s"\n' "$(U_BOOT_VERSION)" \
@@ -3223,8 +3223,6 @@
 #########################################################################
 
 apollon_config		: unconfig
-	@mkdir -p $(obj)include
-	@mkdir -p $(obj)onenand_ipl/board/apollon
 	@echo "#define CONFIG_ONENAND_U_BOOT" > $(obj)include/config.h
 	@$(MKCONFIG) $(@:_config=) arm arm1136 apollon NULL omap24xx
 	@echo "CONFIG_ONENAND_U_BOOT = y" >> $(obj)include/config.mk
@@ -3706,7 +3704,8 @@
 	       $(obj)cpu/blackfin/bootrom-asm-offsets.[chs]
 	@rm -f $(obj)include/bmp_logo.h
 	@rm -f $(obj)nand_spl/{u-boot.lds,u-boot-spl,u-boot-spl.map,System.map}
-	@rm -f $(obj)onenand_ipl/onenand-{ipl,ipl.bin,ipl-2k.bin,ipl-4k.bin,ipl.map}
+	@rm -f $(obj)onenand_ipl/onenand-{ipl,ipl.bin,ipl.map}
+	@rm -f $(ONENAND_BIN)
 	@rm -f $(obj)onenand_ipl/u-boot.lds
 	@rm -f $(TIMESTAMP_FILE) $(VERSION_FILE)
 	@find $(OBJTREE) -type f \