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>

env/embedded.c

@@ -91,6 +91,6 @@ unsigned long env_size __UBOOT_ENV_SECTION__(env_size) = sizeof(env_t);
 /*
  * Add in absolutes.
  */
-GEN_ABS(env_offset, CONFIG_ENV_OFFSET);
+GEN_ABS(env_offset, (CONFIG_ENV_ADDR - CONFIG_SYS_FLASH_BASE));
 
 #endif /* ENV_IS_EMBEDDED */