configs: ls1046aqds: Configure environment related configs

LS1046A-QDS board requires updation in few environment configs in TFA
defconfigs of the board.

Following are the changes:
- Update CONFIG_ENV_ADDR
- Update CONFIG_ENV_SECT_SIZE
- Enable CONFIG_SYS_RELOC_GD_ENV_ADDR

Signed-off-by: Kuldeep Singh <kuldeep.singh@nxp.com>
[Rebased]
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>