common: env: support sata device

common: env: support sata device

Introduce env support for sata device.
1. Implement write_env/read_env/env_relocate_spec/saveenv/sata_get_env_dev
2. If want to enable this feature, define CONFIG_ENV_IS_IN_SATA, and
   define CONFIG_SYS_SATA_ENV_DEV or implement your own sata_get_ev_dev.

Signed-off-by: Peng Fan <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Joe Hershberger <[email protected]>
Cc: Bin Meng <[email protected]>
Cc: Stefan Roese <[email protected]>
Cc: Heiko Schocher <[email protected]>
Cc: Stuart Longland <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Tom Rini <[email protected]>
Reviewed-by: Tom Rini <[email protected]>