libfdt: Introduce new ARCH_FIXUP_FDT option

Add new Kconfig option to disable arch_fixup_fdt() calls for cases where
U-Boot shouldn't update memory setup in DTB file.
One example of usage of this option is to boot OS with different memory
setup than U-Boot use.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/Kconfig b/Kconfig
index ef12f9f..626e82f 100644
--- a/Kconfig
+++ b/Kconfig
@@ -342,6 +342,15 @@
 	help
 	  TODO: Move CONFIG_SYS_CLK_FREQ for all the architecture
 
+config ARCH_FIXUP_FDT
+	bool "Enable arch_fixup_fdt() call"
+	depends on ARM || MIPS
+	default y
+	help
+	  Enable FDT memory map syncup before OS boot. This feature can be
+	  used for booting OS with different memory setup where the part of
+	  the memory location should be used for different purpose.
+
 endmenu		# Boot images
 
 source "common/Kconfig"