dm: core: Change platform specific translation-offset handling

Testing has shown that the current DM implementation of a platform /
board specific translation offset, as its needed for the SPL on MVEBU
platforms is buggy. The translation offset is confingured too late,
after the driver bind functions are run. This may result in incorrect
address translations. With the current implementation its not possible
to configure the offset earlier, as the DM code has not run at all.

This patch now removed the set_/get_translation_offset() calls and
moves the translation offset into the GD variable translation_offset.
This variable will get used when CONFIG_TRANSLATION_OFFSET is enabled.
This option is enabled only for MVEBU on ARM32 platforms, where its
currenty needed and configured in the SPL.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Pierre Bourdon <delroth@gmail.com>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Simon Glass <sjg@chromium.org>
Cc: Heiko Schocher <hs@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Tested-by: Pierre Bourdon <delroth@gmail.com>
Tested-by: Baruch Siach <baruch@tkos.co.il>
diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig
index ddf2fb3..2d195ae 100644
--- a/drivers/core/Kconfig
+++ b/drivers/core/Kconfig
@@ -225,6 +225,15 @@
 	  used for the address translation. This function is faster and
 	  smaller in size than fdt_translate_address().
 
+config TRANSLATION_OFFSET
+	bool "Platforms specific translation offset"
+	depends on DM && OF_CONTROL
+	help
+	  Some platforms need a special address translation. Those
+	  platforms (e.g. mvebu in SPL) can configure a translation
+	  offset by enabling this option and setting the translation_offset
+	  variable in the GD in their platform- / board-specific code.
+
 config OF_ISA_BUS
 	bool
 	depends on OF_TRANSLATE