Convert CONFIG_SYS_I2C_LEGACY to Kconfig and add CONFIG_[ST]PL_SYS_I2C_LEGACY

First, we convert CONFIG_SYS_I2C_LEGACY to Kconfig.  Next, as you cannot
have SYS_I2C_LEGACY and DM_I2C at the same time, introduce
CONFIG_SPL_SYS_I2C_LEGACY so that we can enable the legacy option only
in SPL.  Finally, for some PowerPC cases we also need
CONFIG_TPL_SYS_I2C_LEGACY support.  Convert all of the existing users to
one or more symbols.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/board/compulab/common/Makefile b/board/compulab/common/Makefile
index 842fb3b..25dad49 100644
--- a/board/compulab/common/Makefile
+++ b/board/compulab/common/Makefile
@@ -5,6 +5,6 @@
 # Author: Igor Grinberg <grinberg@compulab.co.il>
 
 obj-y				+= common.o
-obj-$(CONFIG_SYS_I2C_LEGACY)		+= eeprom.o
+obj-$(CONFIG_$(SPL_)SYS_I2C_LEGACY)	+= eeprom.o
 obj-$(CONFIG_LCD)		+= omap3_display.o
 obj-$(CONFIG_SMC911X)		+= omap3_smc911x.o
diff --git a/board/compulab/common/eeprom.h b/board/compulab/common/eeprom.h
index 51c8acf..9bd7604 100644
--- a/board/compulab/common/eeprom.h
+++ b/board/compulab/common/eeprom.h
@@ -10,7 +10,7 @@
 #define _EEPROM_
 #include <errno.h>
 
-#ifdef CONFIG_SYS_I2C_LEGACY
+#if CONFIG_IS_ENABLED(SYS_I2C_LEGACY)
 int cl_eeprom_read_mac_addr(uchar *buf, uint eeprom_bus);
 u32 cl_eeprom_get_board_rev(uint eeprom_bus);
 int cl_eeprom_get_product_name(uchar *buf, uint eeprom_bus);