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/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 49f94f0..79c669a 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -209,6 +209,8 @@
 	select DRAM_SUN4I
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
+	imply SPL_SYS_I2C_LEGACY
+	imply SYS_I2C_LEGACY
 
 config MACH_SUN5I
 	bool "sun5i (Allwinner A13)"
@@ -219,6 +221,8 @@
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
 	imply CONS_INDEX_2 if !DM_SERIAL
+	imply SPL_SYS_I2C_LEGACY
+	imply SYS_I2C_LEGACY
 
 config MACH_SUN6I
 	bool "sun6i (Allwinner A31)"
@@ -245,6 +249,8 @@
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
+	imply SPL_SYS_I2C_LEGACY
+	imply SYS_I2C_LEGACY
 
 config MACH_SUN8I_A23
 	bool "sun8i (Allwinner A23)"
@@ -303,6 +309,7 @@
 	select SUNXI_DRAM_DW
 	select SUNXI_DRAM_DW_32BIT
 	select PHY_SUN4I_USB
+	imply SPL_SYS_I2C_LEGACY
 
 config MACH_SUN8I_V3S
 	bool "sun8i (Allwinner V3/V3s/S3/S3L)"