env: Finish migration of common ENV options

- In ARMv8 NXP Layerscape platforms we also need to make use of
  CONFIG_SYS_RELOC_GD_ENV_ADDR now, do so.
- On ENV_IS_IN_REMOTE, CONFIG_ENV_OFFSET is never used, drop the define
  to 0.
- Add Kconfig entry for ENV_ADDR.
- Make ENV_ADDR / ENV_OFFSET depend on the env locations that use it.
- Add ENV_xxx_REDUND options that depend on their primary option and
  SYS_REDUNDAND_ENVIRONMENT
- On a number of PowerPC platforms, use SPL_ENV_ADDR not CONFIG_ENV_ADDR
  for the pre-main-U-Boot environment location.
- On ENV_IS_IN_SPI_FLASH, check not for CONFIG_ENV_ADDR being set but
  rather it being non-zero, as it will now be zero by default.
- Rework the env_offset absolute in env/embedded.o to not use
  CONFIG_ENV_OFFSET as it was the only use of ENV_OFFSET within
  ENV_IS_IN_FLASH.
- Migrate all platforms.

Cc: Wolfgang Denk <wd@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: uboot-stm32@st-md-mailman.stormreply.com
Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
diff --git a/configs/goflexhome_defconfig b/configs/goflexhome_defconfig
index 5fa8b4d..c7e1169 100644
--- a/configs/goflexhome_defconfig
+++ b/configs/goflexhome_defconfig
@@ -4,6 +4,8 @@
 CONFIG_KIRKWOOD=y
 CONFIG_SYS_TEXT_BASE=0x600000
 CONFIG_TARGET_GOFLEXHOME=y
+CONFIG_ENV_SIZE=0x20000
+CONFIG_ENV_OFFSET=0xC0000
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_IDENT_STRING="\nSeagate GoFlex Home"
 # CONFIG_SYS_MALLOC_F is not set