arm: socfpga: fix 3 boards missing env var "socfpga_legacy_reset_compat"

This fixes 3 boards that don't use CONFIG_EXTRA_ENV_SETTINGS from
socfpga_common.h. They need to enable reset manager compatibility
mode unless all peripheral drivers in Linux support reset handling.

Fixes: commit 4b2e32ef ("arm: socfpga: gen5: deassert peripheral reset by default")
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reported-by: Wolfgang Grandegger <wg@aries-embedded.de>