Convert CONFIG_ENV_IS_IN_MMC/NAND/UBI and NOWHERE to Kconfig

This converts the following to Kconfig:
   CONFIG_ENV_IS_IN_MMC
   CONFIG_ENV_IS_IN_NAND
   CONFIG_ENV_IS_IN_UBI
   CONFIG_ENV_IS_NOWHERE

In fact this already exists for sunxi as a 'choice' config. However not
all the choices are available in Kconfig yet so we cannot use that. It
would lead to more than one option being set.

In addition, one purpose of this series is to allow the environment to be
stored in more than one place. So the existing choice is converted to a
normal config allowing each option to be set independently.

There are not many opportunities for Kconfig updates to reduce the size of
this patch. This was tested with

   ./tools/moveconfig.py -i CONFIG_ENV_IS_IN_MMC

And then manual updates.  This is because for CHAIN_OF_TRUST boards they
can only have ENV_IS_NOWHERE set, so we enforce that via Kconfig logic
now.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index bd3e7d3..94412ba 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -59,6 +59,7 @@
 	select SUNXI_DRAM_DW_32BIT
 	select SUNXI_GEN_SUN6I
 	select SUPPORT_SPL
+	imply ENV_IS_IN_MMC
 
 choice
 	prompt "Sunxi SoC Variant"
@@ -70,6 +71,7 @@
 	select ARM_CORTEX_CPU_IS_UP
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
+	imply ENV_IS_IN_MMC
 
 config MACH_SUN5I
 	bool "sun5i (Allwinner A13)"
@@ -87,6 +89,7 @@
 	select SUNXI_GEN_SUN6I
 	select SUPPORT_SPL
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
+	imply ENV_IS_IN_MMC
 
 config MACH_SUN7I
 	bool "sun7i (Allwinner A20)"
@@ -97,6 +100,7 @@
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
+	imply ENV_IS_IN_MMC
 
 config MACH_SUN8I_A23
 	bool "sun8i (Allwinner A23)"
@@ -107,6 +111,7 @@
 	select SUNXI_GEN_SUN6I
 	select SUPPORT_SPL
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
+	imply ENV_IS_IN_MMC
 
 config MACH_SUN8I_A33
 	bool "sun8i (Allwinner A33)"
@@ -132,6 +137,7 @@
 	select ARCH_SUPPORT_PSCI
 	select MACH_SUNXI_H3_H5
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
+	imply ENV_IS_IN_MMC
 
 config MACH_SUN8I_R40
 	bool "sun8i (Allwinner R40)"