of: clean up OF_CONTROL ifdef conditionals

We have flipped CONFIG_SPL_DISABLE_OF_CONTROL.  We have cleansing
devices, $(SPL_) and CONFIG_IS_ENABLED(), so we are ready to clear
away the ugly logic in include/fdtdec.h:

 #ifdef CONFIG_OF_CONTROL
 # if defined(CONFIG_SPL_BUILD) && !defined(SPL_OF_CONTROL)
 #  define OF_CONTROL 0
 # else
 #  define OF_CONTROL 1
 # endif
 #else
 # define OF_CONTROL 0
 #endif

Now CONFIG_IS_ENABLED(OF_CONTROL) is the substitute.  It refers to
CONFIG_OF_CONTROL for U-boot proper and CONFIG_SPL_OF_CONTROL for
SPL.

Also, we no longer have to cancel CONFIG_OF_CONTROL in
include/config_uncmd_spl.h and scripts/Makefile.spl.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/core/root.c b/drivers/core/root.c
index 12d0460..78ab00c 100644
--- a/drivers/core/root.c
+++ b/drivers/core/root.c
@@ -114,7 +114,7 @@
 	ret = device_bind_by_name(NULL, false, &root_info, &DM_ROOT_NON_CONST);
 	if (ret)
 		return ret;
-#ifdef CONFIG_OF_CONTROL
+#if CONFIG_IS_ENABLED(OF_CONTROL)
 	DM_ROOT_NON_CONST->of_offset = 0;
 #endif
 	ret = device_probe(DM_ROOT_NON_CONST);
@@ -145,7 +145,7 @@
 	return ret;
 }
 
-#ifdef CONFIG_OF_CONTROL
+#if CONFIG_IS_ENABLED(OF_CONTROL)
 int dm_scan_fdt_node(struct udevice *parent, const void *blob, int offset,
 		     bool pre_reloc_only)
 {
@@ -198,7 +198,7 @@
 		return ret;
 	}
 
-	if (OF_CONTROL) {
+	if (CONFIG_IS_ENABLED(OF_CONTROL)) {
 		ret = dm_scan_fdt(gd->fdt_blob, pre_reloc_only);
 		if (ret) {
 			debug("dm_scan_fdt() failed: %d\n", ret);